BEIRUT: Airstrikes on villages and towns held by the Islamic State group in eastern Syria have killed and wounded dozens a day after an attack by the extremists killed more than 120 pro-government fighters and briefly cut off the highway linking the capital, Damascus, with eastern Syria, opposition activists said Saturday.

It was not immediately clear if the airstrikes on areas including Mayadeen, Boukamal, Bouleil, Bouomar and Mushassan were carried out by the Russians or the U.S.-led coalition. Syrian troops have been advancing in the eastern province of Deir el-Zour against ISIS under the cover of Russian airstrikes while the Kurdish-led Syrian Democratic Forces are marching against the extremists under the cover of airstrikes by the U.S.-led coalition.

The airstrikes came after two days of clashes between Syrian government forces and their allies against ISIS fighters in central and eastern Syria that left nearly 200 dead on both sides. Syrian troops and their allies have regained most of the areas they had lost earlier.

The Britain-based Syrian Observatory for Human Rights said Saturday’s airstrikes and those the night before killed 18 people, including two children.

“They burnt Bouleil overnight,” said Omar Abou Leila of the monitoring group DeirEzzor 24, adding that 13 people were killed in Bouleil and nine in Boukamal alone.

Activists said that airstrikes on rebel-held parts of northern Syria have stopped after more than a week of bombing that left hundreds dead or wounded. The attacks on Idlib and Aleppo came after militants launched an attack against government forces Sept. 19, capturing some areas before losing them.

Russian Defense Ministry spokesman Maj. Gen. Igor Konashenkov said that all attempts by ISIS and al-Qaida-linked militants to launch offensives in the provinces of Deir el-Zour and Idlib in the northwest were repelled.

Konashenkov said the militants suffered “the most serious losses in months” and their capability has been significantly diminished.

He said that Russian airstrikes killed 2,359 militants and wounded about 2,700 others over 10 days starting Sept. 19. Russia joined Syria’s war on Sept. 30, 2015.