Turkey is turning away Syrian families without passports after a refugee influx, the Turkish Humanitarian Relief Foundation (IHH) said today.
One of the Syrian opposition's most vocal allies, Turkey has taken in hundreds of thousands of Syrian refugees.
But recently Turkey started to claim its resources have been stretched at the Turkish border.
"Camps in Kilis are at full capacity unfortunately, but there are free spaces in our other camps", a press officer for Turkey's state AFAD disaster agency said, referring to refugee camps near the Turkish border.
The press officer said Ankara is sticking to its "open border" policy and refugees will be accepted "following necessary security controls".
A camp inside Syria near the Syrian Bab al-Salam border crossing, about 50 km north of Aleppo, is also full, IHH's Kilis media officer said, adding that numbers there had risen to 25,000 from 14,000 in the last week.
The media officer said "the Syrians who don't get into Turkey are sheltering in Syria - just under blankets". Night-time temperatures in the area fall below freezing.
Turkish police at Oncupinar border post across from Bab al-Salam said restrictions applied to those without passports, but that the crossing was open, with no big crowd at the gate.
Further east, the opposition observatory said that for the last 18 days Turkish authorities have prevented more than 2,000 refugees, including women and children, from crossing into Turkey after fleeing the city of Raqqa.
"Most of them are living in the open, near to the barbed wire at the Tel Abyad border", the British-based watchdog said.