ISIS Redux: The Central Syria Insurgency in April 2021

May 3, 2021
Gregory Waters  —  Research Analyst

Following is the April 2021 installment of “ISIS Redux: The Central Syria Insurgency,” a monthly chronicle of attacks by the terrorist group ISIS in central Syria. Previous editions of ISIS Redux can be viewed through the following links: March, February, January, December, November, October, September, August, July, June, May, and April. A full background and analysis of ISIS’s resurgence in Syria, including its methodology, can also be explored herehere and here.

ISIS militants carried out at least 30 confirmed attacks in April, killing at least 24 pro-Assad regime fighters and three civilians, while wounding at least 30 in the Homs, Deir Ez Zor, Raqqa, Hama, and Aleppo governorates. Although the rate of ISIS attacks during April dropped back to that seen in February, ISIS continued to shift its focus from civilians back to military targets. Thus, while there were 30 attacks in April, compared to 38 in March, 24 of this month’s attacks hit military targets compared to just 26 in March. Also, slightly more security personnel were confirmed killed in April than in March.

High quality* attacks in April dropped to their lowest point in a year. This can largely be attributed to the complete lack of confirmed high quality attacks in Deir Ez Zor and a significant drop in Hama. That being said, none of April’s six high quality attacks solely targeted civilians, compared to four of the 13 in March and two of nine attacks in February.

While ISIS’s choice of targets this month continued the trend begun in late March its attack type did not, with the group using mines and IEDs at a slightly higher rate this month. Across March, ISIS used mines or IEDs for 47 percent of its attacks, heavily concentrated in the first half, and to a lesser extent, the last week of the month. In April, mines and IEDs accounted for 50 percent of confirmed attacks, which were again slightly concentrated in the first half and last days of the month.

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Attacks in April continued to increase in Homs (13) and south Aleppo (3), while decreasing to February levels in Deir Ez Zor (5) and Raqqa (2). Attacks dropped sharply in Hama (7), ending a two-month climb. Despite the overall drop in attacks on civilians, ISIS’s targeting of civilians in Hama occurred at a higher rate than in the previous two months. High quality attacks were carried out in every province except Deir Ez Zor in April (three in Homs and one each in Raqqa, Hama, and Aleppo).

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ISIS activity in east Hama halved in April, returning to January 2021 levels. All but two incidents involved mines or IEDs, compared to 12 of 16 attacks in March and all 14 attacks in February. All five mine/IED attacks in April occurred in established hotspots around Ithriyah and east of Salamiyah.

However, the remaining two incidents were extremely significant. On April 6, ISIS cells carried out a series of ambushes against at least two convoys of civilians and local security forces near the Homs-Hama border. As many as 70 people were kidnapped and several security members were killed and injured. Hours later, regime forces in Salamiyah exchanged imprisoned ISIS family members for nearly all of the civilians. This was the first known instance of ISIS using captured civilians to free its fighters’ families.


ISIS activity in Homs continued at a high rate, despite very few attacks in the first three weeks of April. Attacks were concentrated in three areas: Palmyra, Sukhnah, and Kawm. As in the past, Sukhnah remained the center of ISIS activity in the province, with the group hitting regime forces with IEDs on several occasions, including a double-tap IED attack on April 24, when militants detonated a second device as soldiers arrived to inspect the wrecked vehicle. ISIS militants, still in control of the Wadi Doubayat area south of Sukhnah, also ambushed a regime patrol near there early in the month.

In the Palmyra region, ISIS continued to lay mines and IEDs, hitting regime forces at least four times and civilians once. In the northeast area of the governorate, ISIS cells based in the Kawm-Jabal Bishri region clashed at least twice with regime forces, attempting to secure the area around Kawm, while also attacking regime forces with a mine on one of the roads approaching Kawm from the south. To the north, at least one soldier was killed in clashes near the Kawm-Kadir area on the Homs-Raqqa border.

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Map of ISIS attacks in Homs in April 2021 (highlighted dots). Not mapped is one additional attack killing a Lebanese Hezbollah fighter somewhere in the Badia.

Deir Ez Zor

After a small increase in attacks in March, April brought a drop in Deir Ez Zor activity. The regime’s early 2021 Shoula operations and a second, smaller operation late in April appear to have effectively kept ISIS forces from coming out of the desert to launch attacks. Of the five confirmed attacks in April, four occurred in the first two weeks and only one was of note. On April 5, a suspected ISIS member threw a grenade into a checkpoint west of the town of Tabni, injuring and possibly killing some of the men inside. Tabni lies north of Deir Ez Zor city, and its countryside was the site of intense fighting in August. On October 2, 2020, ISIS fighters wearing suicide belts attacks the town’s police station, killing several. While there has not been any confirmed ISIS activity since early November 2020, the fact that someone was able to get close enough to a checkpoint to a throw a grenade suggests there are still ISIS sympathizers in or around the town.

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Map of ISIS attacks in Deir Ez Zor in April 2021 (highlighted dots). Not mapped are two additional attacks that occurred in unspecified locations in the province.

Raqqa and Aleppo

ISIS activity continued to increase in the west Raqqa and south Aleppo areas following the fake checkpoint attack near Dibsi Afnan in late March. In the early morning of April 19, ISIS fighters in a pickup truck and on motorcycles attacked a family’s house south of Dibsi Afnan on the Raqqa-Aleppo border. The militants and civilians engaged in a 30-minute firefight that left one civilian dead and one wounded. The family had been targeted by ISIS last year as well in an attack that killed the head of the household and one of his sons.

The next day, five members of the regime’s Military Security disappeared while combing one of the abandoned villages near Resafa, presumably kidnapped or killed by ISIS militants. Three days later, on April 23, a small group of ISIS fighters attacked a new 5th Corps outpost on the highway at the Hama-Aleppo-Raqqa administrative border. This ISIS attack, carried out at night and employing thermal optics, came as the regime began moving new troops into the governorate.

ISIS activity dropped significantly with the arrival of new forces and extensive patrols, with only one more small clash occurring somewhere south of Resafa on April 29. Meanwhile, on April 28, ISIS claimed the killing of two regime soldiers by hitting their motorcycle with an IED near Tel Daman, west of Khanasir. This marked the farthest northwest attack of an ISIS Badia cell to date, possibly signaling an expansion of Khanasir-based cells.

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Map of ISIS attacks in Raqqa and Aleppo in April 2021 (highlighted dots). Not mapped is one additional attack that occurred somewhere south of Resafa.

Regime Operations

The Syrian regime and it’s Iranian and Russian allies completed extensive anti-ISIS operations in Deir Ez Zor in early March, as well as smaller operations in northeast Homs, around Tuwaynan, and in east Hama, around Rahjan. These operations ended by mid-March, allowing a surge of ISIS activity to occur. Simultaneously, the regime began bolstering its forces in Homs and Deir Ez Zor, sending extensive reinforcements from the 4th Armored Division, including tanks, to Palmyra, Sukhnah, and Deir Ez Zor city.

In April, these forces began new operations. The Iranian-backed Afghan Liwa Fatemiyoun launched new sweeps around Shoula, likely in response to renewed ISIS activity there in late March. These forces, alongside local National Defense Forces (NDF) units, also appear to have launched a still-ongoing operation in the Mayadin countryside in late April. Other anti-ISIS sweeps took place in east Hama, the Maskanah countryside in Aleppo, and in the mountains between Palmyra and Sukhnah. This last area is where the Russian Ministry of Defense made the absurd claim of killing 200 ISIS militants in a bombing run. According to local sources and unofficial ISIS accounts, only one to three fighters were killed in the strikes.

Most significantly, beginning in mid-April, the regime initiated what appeared to be a multi-pronged operation in northeast Homs and southern Raqqa. Units from the newly arrived 4th Division, assisted by Syrian private military contractors and the NDF, pushed north from Sukhnah to secure the strategic town of Kawm. Kawm is the last major urban center along the highway connecting Sukhnah with Resafa in Raqqa. The road also runs alongside several oil and gas fields.

Regime forces have a history of fighting ISIS cells in and around Kawm, entering the town for a period only to be pushed out again. After again entering Kawm on April 22, regime forces attempted to push east into the heart of ISIS territory, but were ambushed after advancing about 5km, losing their sector commander in the process. The forces withdrew entirely from the town, but returned the next day after the Russian Air Force bombed the countryside. These forces would again clash with ISIS around Kawm on April 27. As of this writing, they remain in control of the town.

Meanwhile, the Russian-backed 5th Corps sent new units to southern Raqqa during the second half of the month. These new units took up positions along the Ithriya-Tabqa highway, reinforced the garrison in Resafa, and began pushing south, adding new outposts alongside the oil fields between Resafa and Kawm. ISIS conducted a night-time attack on one of these new positions along the Ithriya-Tabqa highway on April 23. On April 28, 5th Corps fighters patrolling near the oil fields south of Resafa ambushed and killed several ISIS fighters, while another patrol lost at least one soldier to an ISIS ambush the following day.

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Map showing regime operations in northeast Homs and south Raqqa in April. Dots are locations of ISIS attacks in 2021.

This Raqqa deployment signals a major shift in the Syrian regime’s attitude towards the Badia. Southern Raqqa has always been the weakest of the regime’s Badia regions, with forces there frequently undermanned, undertrained, and unsupported by the high command and Air Force. For much of 2020, pro-regime units in southern Raqqa struggled to effectively patrol or conduct anti-ISIS operations and almost never received air support. The fact that Damascus is now emphasizing what was once its least prioritized front suggests the Syrian Arab Army (SAA) leadership has finally acknowledged the scale of the ISIS problem and is ready to devote significant resources to fight it.

Looking Ahead

The regime’s actions in April, especially in Raqqa, constitute the second major obstacle ISIS has faced this year (the first being the Shoula operations in January and February). The Badia is now flooded with regime troops, and while they largely remain garrisoned in major towns where ISIS is already unlikely to attack, ISIS cells will need to adjust to the new emphasis on patrols and extensive outpost building. It will likely take several weeks for ISIS cells to adjust their tactics in response to these developments. In the meantime, they will—as one 5th Corps soldier told this author—continue to rely on “mines and IEDs and harassing fire from long distances.” Unfortunately for analytical purposes, such attacks are the least reported by loyalist media, further limiting our ability to understand what is actually happening in the Badia.

May will be an important month for gauging the strength of ISIS in the Badia. The group has spent the past year laying the groundwork for a resurgence: Expanding into new areas of operations, smuggling in and training new fighters, and building tendrils into the local economy. This month’s troop surge has forced cells to pull back into their deep rural hideouts. This comes at the same time as reports that ISIS has shifted fighters out of the Badia and into northeast Syria and Iraq to assist in Ramadan attacks. If and when ISIS is able to hit back and turn newly “cleared” areas back into “contested” areas will reveal much about the longevity of this insurgency.

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Map of locatable ISIS attacks (highlighted dots) in April 2021. This map does not include seven attacks which did not have specific locations attributed to them: two "east Salamiyah" Hama attacks, one “Badia” Homs attack, one south Raqqa attack, and one "Deir Ez Zor countryside" attack. To view an interactive version of this map, please click here.


*High quality attacks are defined as attacks behind frontlines, those that result in seized positions, target regime officers, involve coordinated attacks on multiple positions, fake checkpoints, ambushes on military convoys, or attacks on checkpoints that kill at least three soldiers or lead to POWs.

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