Beirut: Syrian Kurdish authorities evacuated thousands of civilians from Kurdish areas of a city in northeastern Syria on a second day of government air strikes on Friday, a spokesman for the Kurdish YPG militia said.
This week's fighting in Hasaka, which is divided into zones of Kurdish and Syrian government control, marks the most violent confrontation between the YPG and Damascus in more than five years of civil war, YPG spokesman Redur Xelil said.
Dozens of civilians have been killed in the last 48 hours, he told Reuters. The YPG is at the heart of a US-led campaign against IS in Syria, and controls swathes of the north where Kurdish groups have set up their own government.
The government, which opposes Syrian Kurdish autonomy, has yet to speak about this week's fighting during which it has used the air force against Kurdish groups for the first time.
Most of those evacuated were women and children. "Whoever can bear arms is fighting the regime and its gangs," Xelil said.
"Our situation is so far defensive but it will change all the while the regime escalates in this way," he said.
The YPG and Syrian government have mostly avoided confrontation during the multi-sided war that has turned Syria into a patchwork of areas held by the state and an array of armed factions.
Assad has focused mostly on fighting rebels who have been battling to oust him in western Syria. The Syrian and Russian air forces are routinely deployed in the war in western Syria.
The YPG, or People's Protection Units, has meanwhile prioritised carving out and safeguarding predominantly Kurdish regions of northern Syria. The group has ties to the Kurdistan Workers Party (PKK) in Turkey.
While the YPG controls most of the northeast, the Syrian government has maintained footholds in the cities of Hasaka and Qamishli at the border with Turkey. The YPG has controlled most of Hasaka city since last year.
It is the second major eruption of fighting between the YPG and Syrian government fighters this year. In April, the sides fought several days of lethal battles in Qamishli, north of Hasaka city. It is also mostly YPG-held.
The Syrian Observatory for Human Rights, which reports on the war using an activist network, said Kurdish forces had gained ground in the southern part of the city.
Rami Abdulrahman, Observatory director, said the fighting began this week after pro-government militiamen detained a number of Kurdish youths, a step that had followed advances by Kurdish security forces towards government-held areas.
Naser Haj Mansour, a Kurdish official in the YPG-affiliated Syria Democratic Forces alliance, said Kurdish forces had taken some additional positions including an economics college.
The Observatory said many civilians were fleeing areas affected by the fighting to safety, and hospitals in Kurdish areas of the city did not have enough blood and medicines to treat the wounded.