The Syrian regime opened on Thursday a humanitarian corridor in the northwestern Idlib region.
Damascus "announces the opening of a humanitarian corridor in the (town) of Soran," reported the SANA state news agency citing a foreign ministry source.
It said the corridor would allow civilians to leave the southern part of Idlib province and the north of Hama, where the regime has advanced against opposition factions with fierce air and ground attacks.
Regime forces also opened fire on a Turkish observation post in northwest Syria, two Turkish officials told Reuters on Thursday, but there were no Turkish casualties.
The incident came after an airstrike halted a Turkish military convoy and killed three civilians on Monday as the convoy headed south towards another observation post.
Turkey has 12 observation posts in northwest Syria, set up under an agreement with Russia and Iran.
On Wednesday, Turkish presidential spokesman Ibrahim Kalin said all of Turkey's observation posts will remain in place, and support to the posts will continue.
The regime took full control Wednesday of Khan Sheikoun, a key town in Idlib, surrounding opposition-backing Turkish forces at a nearby observation post, a war monitor said.
The advance on the town comes after months of airstrikes on the area by the regime and its Russian ally.
"Regime forces took full control of the town of Khan Sheikhoun and are currently clearing it of mines," said Syrian Observatory for Human Rights chief Rami Abdel Rahman.
Pro-regime fighters have now "surrounded an area stretching from the south of Khan Sheikhoun into northern Hama province, cutting off all roads out" for Turkish troops in the nearby town of Morek, he said.
The Observatory said 21 anti-regime fighters including 18 extremists were killed in Wednesday's clashes, along with 10 regime or loyalist fighters.
The takeover came after days of heavy fighting against opposition and extremist factions that control the Idlib region, which sits on the Turkish border and is the last major stronghold of opposition to the Russia-backed regime of Bashar Assad.
It has been administered since January by the Hayat Tahrir al-Sham alliance, which is led by extremists from Syria's former al-Qaeda affiliate.
The region of some three million people was supposed to be protected by a buffer zone deal signed last September by Moscow and Ankara, but regime and Russian forces have subjected it to heavy bombardment since late April.
Around 890 civilians have been killed since then, according to the Britain-based Observatory.
More than 400,000 people have been displaced by the fighting over the same period, the United Nations says.
The war in Syria has killed more than 370,000 people since it started with the brutal repression of anti-regime protests in 2011.
