Hundreds flee Turkish advance on Afrin city
Turkey-led rebels have advanced to the outskirts of Afrin city since launching an assault on the wider Kurdish enclave of the same name on January 20.
"More than 2,000 civilians have arrived in the area of Nubul" controlled by pro-regime forces after fleeing the enclave, said the Syrian Observatory for Human Rights.
"Several hundred more are still on the roads" heading out of the region, the Britain-based Observatory said.
Turkish forces and their allies on Saturday arrived within less than two kilometres (one mile) of the city, sparking fears it could become besieged.
Afrin city - the main urban centre in the enclave on the Turkish border - is home to around 350,000 people, the Observatory says.
A journalist contributing to AFP saw dozens of cars and buses loaded with civilians and their belongings queuing as they waited to exit the enclave.
The only road out of Afrin for civilians wishing to escape the Turkish offensive is via Nubul and the nearby area of Zahra.
With the latest civilians leaving, these two areas have become home to around 16,000 displaced from the Afrin region, the Observatory says.
The areas are so crowded that those fleeing fighting have resorted to living in mosques and schools, he said.
A spokeswoman for the UN's humanitarian coordination office (OCHA) in Damascus said the situation inside Afrin was looking "very serious".
"As the military operations get closer to Afrin city, they are putting a lot of people at risk, in addition to displaced people in the city," Linda Tom said.
Thousands have sought refuge in the city, after escaping fighting in other areas of the Kurdish enclave.
"We're trying to get humanitarian assistance" in, she said.
The Syrian Arab Red Crescent said it was working with the United Nations to ferry aid into the enclave.
Only one aid convoy has made it in since the start of the assault, with food and other supplies for just 50,000 people on March 1.
On Monday, the Observatory reported violent clashes on the outskirts of Afrin city, as pro-Ankara rebels advanced seizing control of several villages in other parts of the region.
Turkey accuses the People's Protection Units (YPG) controlling Afrin of being "terrorists".
60 percent in pro-Ankara hands
The Observatory says pro-Ankara forces have captured around 60 percent of the Afrin enclave since January 20.
The YPG led a US-backed alliance that succeeded in expelling the Islamic State group from much of Syria.
Hundreds of Kurdish and Arab forces from the anti-IS alliance have left the fight against the militants to head to Afrin to help.
And after a call for help from Damascus, pro-regime fighters have also been deployed on several fronts.
The Observatory says more than 200 civilians have been killed since the Afrin battle began, but Turkey denies the reports and says it takes the "utmost care" to avoid civilian casualties.
Turkey fears Syria's Kurds will establish an autonomous region on its borders.
It has accused the YPG of being a "terrorist" extension to the Kurdistan Workers' Party (PKK), which has fought a three-decade insurgency in southeast Turkey.