BEIRUT, Apirl 4, (AP): Syrian troops and allied militiamen pressed on with an offensive against Islamic State militants in central Syria on Monday, clashing with the extremists around the town of Qaryatain a day after it was captured by pro-government forces. The push into Qaryatain took place under the cover of Russian airstrikes and dealt another setback to IS in Syria a week after the army retook the historic town of Palmyra from the group.

Syria’s state news agency, SANA, said the army was fighting IS militants in areas around Qaryatain Monday, as well as in farms east and north of Palmyra. The capture of Qaryatain deprives IS of a main base in central Syria and could be used by government forces in the future to launch attacks on IS-held areas near the Iraqi border.

Qaryatain used to be home to a sizable Christian population and lies midway between Palmyra and the capital, Damascus. Activists said last summer that Qaryatain had a mixed population of around 40,000 Sunni Muslims and Christians, as well as thousands of internally displaced people who had fl ed from the nearby city of Homs.

Many of the Christians fl ed the town after it came under attack by IS. Dozens of Qaryatain’s Christians and other residents have been abducted by IS. While the town was under Islamic State control, some were released while others were made to sign pledges to pay a tax imposed on non-Muslims. Also on Monday, a senior US official said the US carried an airstrike on Sunday night in northwest Syria targeting a senior member of al-Qaeda. He did not confirm if the al-Qaeda member, named as Abu Firas al-Souri, had been killed.

The official spoke on condition of anonymity because he wasn’t authorized to discuss the operation. The SITE Intelligence Group, which monitors jihadi websites, said Abu Firas al-Souri died in US strikes while the Britain- based Syrian Observatory for Human Rights said the jets were thought to belong to the Syrian or Russian Air Forces. It said they targeted the headquarters of Jund al- Aqsa, an extremist group that fi ghts alongside al-Qaeda’s Syrian affiliate, the Nusra Front.