The Syrian Observatory for Human Rights said on Sunday that rebel group Failaq al-Sham has started withdrawing its forces and heavy arms from a demilitarised zone in northwest Syria.

The group is the first to comply with a requirement to leave a demilitarised buffer zone set up by Turkey and Russia to avert a Russian-backed Syrian army offensive, Rami Abdulrahman, head of the UK-based war monitor told Reuters.

Rebel sources could not immediately be reached for comment.