A regime military vehicle destroyed by an Islamic State attack in eastern Homs Province

The Islamic State has killed at least 35 pro-Assad troops in central Syria, according to local sources.

ISIS attacked in the desert in eastern Homs Province, north of the ancient city of Palmyra, and in neighboring Deir ez-Zor Province. Among the operations was a strike on a regime convoy near the Al-Bushri Mountain and the town of al-Sukhnah.

A pro-Assad blog said more than 50 regime troops have been killed in April by Islamic State ambushes.

The latest attacks are the most significant by the Islamic State since the group lost its last villages, in eastern Syria near the Iraqi border, last month in an offensive by US-supported, Kurdish-led forces.

ISIS fighters are still in the desert in central Syria, surrounded by pro-Assad units.

The Islamic State held parts of Syria, including the city of Raqqa, from 2014. It captured Palmyra, an important Roman city, in May 2015 and December 2016 as well as nearby oil and gas fields. Pro-Assad forces finally regained the area in March 2017.

See Syria Daily, March 3, 2017: With Russia & US Help, Regime Takes Palmyra from ISIS

The regime also suffered losses in western Aleppo Province on Saturday. At least 19 troops, including a Lieutenant Colonel, were killed by a raid by the hardline Islamist bloc Hay’at Tahrir al-Sham. Three HTS fighters died in the attack.

HTS said the attack was a retaliation for ongoing regime shelling, breaking a Russian-Turkish demilitarized zone, on neighboring Idlib Province. The shelling has killed and injured hundreds of civilians and displaced tens of thousands since mid-February.

Regime forces renewed shelling of southeastern Idlib Province overnight, striking Khan Sheikhoun — site of an April 2017 regime sarin attack that killed about 90 people and injured hundreds: