A rebel mortar attack killed four civilians in the Syrian capital on Sunday, as government forces battled Islamic State (ISIS) group jihadists in the northern city of Hasakeh, a monitor said, according to AFP.
The Syrian Observatory for Human Rights said a mortar round struck Revolution Street in central Damascus, killing four people and wounding 13.
Syria's state-run SANA news agency also reported the attack but said three people died.
In Hasakeh, regime troops pressed an offensive they launched on Saturday to dislodge ISIS from districts they have seized in the southern part of the city.
The Britain-based Observatory, which has been monitoring the Syrian conflict since it erupted four years ago, said the troops and jihadists were locked in fierce fighting Sunday.
The jihadist group blew up an explosive-rigged vehicle in Hasakeh, the monitor said, without mentioning casualties.
ISIS seized two neighborhoods in southern Hasakeh on Thursday in a new attempt to seize the provincial capital, causing tens of thousands of people to flee, according to the United Nations.
On Friday, an ISIS suicide bomber killed at least 20 regime troops in Hasakeh, an attack which came hours after the Observatory said ISIS had killed 164 civilians in its offensive on the Kurdish town of Kobane
Meanwhile, government reinforcements have poured into Hasakeh, and Kurdish fighters, who control the city jointly with regime loyalists, have also taken part in the battles.
ISIS also tried to seize Hasakeh last month, but was pushed back by government forces.
The Observatory, which relies on a network of sources inside Syria, also reported on Sunday that the number of civilians killed by ISIS in Kobane had risen to 223.
ISIS’ killing spree began after the extremists entered the Kurdish town at dawn on Thursday.
AFP contributed to this report.