Clashes in Syria's Idlib province between a powerful jihadist group and a key rebel faction intensified overnight, spreading to a border crossing with Turkey, a monitor and AFP correspondent said Friday.
The running battles between the jihadist Hayat Tahrir al-Sham (HTS), led by a former Al-Qaeda affiliate, and the Ahrar al-Sham rebel group have so far killed at least 65 people, including 15 civilians.
The clashes erupted earlier this week, and quickly spread through the province, which is one of the last remaining bastions of opposition-held territory.
Overnight, fierce battles raged in several parts of the province, including inside the Bab al-Hawa border crossing, which was previously fully controlled by Ahrar al-Sham.
"The fighting is now inside the crossing. It has become a battlefield, with part of it under Hayat Tahrir al-Sham's control, and part under Ahrar al-Sham's control," said Observatory director Rami Abdel Rahman.
An AFP correspondent in the province also reported heavy clashes on the outskirts of the town of Binnish and attempts by HTS to break into the village of Ram Hamdan.
HTS and Ahrar once formed the backbone of the Army of Conquest that captured most of Idlib province from the government in 2015.
But tensions between the two factions have been rising for some time and the latest clashes erupted in part over Ahrar's attempts to fly the flag of the Syrian revolution in the provincial capital Idlib city.
HTS is dominated by the Fateh al-Sham faction, which was previously known as Al-Nusra Front before dropping its official designation as Al-Qaeda's Syrian affiliate.
The clashes have been accompanied by sporadic demonstrations against HTS in several parts of the province, including in the town of Sarmada where the jihadists on Wednesday and Thursday opened fire on protests against them.
On Wednesday, the fire killed a media activist participating in the demonstrations in the town.
Both sides have set up new checkpoints, and the fighting has turned parts of the province into virtual ghost towns with residents staying at home for fear of being caught in the fighting.
The Observatory said at least 15 civilians, including four children, have been killed in the fighting so far, including the media activist killed in the Wednesday demonstration in Saraqeb.
Another 50 fighters from both sides have been killed in clashes and executions, the monitor said.
More than 330,000 people have been killed in Syria since the conflict began in March 2011 with anti-government protests.