At least 54 people were killed and dozens wounded when an air strike hit a fuel station in Syria's northern province of al-Raqqa on Thursday, the Syrian Observatory for Human Rights said.
The British-based group, which has a network of activists across Syria, cited an activist in the region saying that more than 110 people were among the dead and wounded.
The attack follows a reported helicopter crash in the town of Douma east of the Syrian capital Damascus earlier today.
An activist in Damascus said rebels had shot down the helicopter. No rebel group has claimed the attack yet.
Rebel fighters seeking to overthrow president Bashar al-Assad have often fired at planes and helicopters used by the Syrian military to bombard opposition strongholds, bringing down a helicopter on the outskirts of Damascus on August 27th.
Three days later fighters in the northern province of Idlib said they had shot down a fighter plane in the northwestern province of Idlib near the Turkish border.
Rebels short of anti-aircraft capability have also launched ground attacks on airforce bases in the north and east of Syria to try to counter the military's air power.
Elsewhere, in Damascus, soldiers raided a Palestinian refugee camp where many Syrians from other parts of the country’s capital and its suburbs have been sheltering, arresting dozens of people in a sweeping operation, the government and opposition groups said.
Syrian TV said an army unit conducted a “special operation” during which about 100 gunmen were captured in the Palestinian refugee camps of Yarmouk and Palestine in Damascus.
The Local Co-ordination Committees activist network reported gunfire and several casualties that accompanied the raid.
The British-based Syrian Observatory for Human Rights said three people were killed and dozens of others were arrested when troops stormed parts of the Yarmouk camp that has provided shelter for many residents of Damascus’s Hajar al-Aswad district, an area that has seen heavy fighting between rebels and government troops in recent days.
Agencies