BEIRUT, April 10, (Agencies): At least 24 Islamic State group fighters and eight civilians were killed in air strikes Sunday on Syria’s Raqa, the de facto capital of the jihadist movement, a monitor said.

It was unclear whether the raids were carried out by Syrian, Russian or US-led coalition warplanes, the Syrian Observatory for Human Rights said. “At least 24 IS members, among them three commanders, as well as eight civilians were killed in air strikes,” Observatory director Rami Abdel Rahman said.

“We do not know whether the warplanes were from the US-led coalition, the Syrian regime or Russia,” he added. Syrian activists say the Islamic State group has launched a major offensive along the Turkish border, seizing two villages near a border town captured by Western-backed rebels two days ago.

The Britain-based Syrian Observatory for Human Rights, which relies on activists inside the country, says IS militants seized Sheikh Reeh and al- Bal on Sunday. The activist-run Azaz Media Center, based in a northern town of the same name, says the extremists exploded seven bombs around Marea and other villages and towns, calling it the fiercest IS offensive in a year.

The IS-linked Aamaq News Agency claims the capture of the two villages and says a suicide operation targeted rebel fighters in opposition-held Kafr Shousha. The Western-backed Free Syrian Army captured the border town of al- Rai from IS on Friday.