BEIRUT: Hundreds of Syrian rebels prepared to head to frontlines in northern Aleppo province on Thursday, after crossing from Turkey to reinforce fighters battling Kurdish militia.

The group of 500 opposition fighters was in the border town of Azaz, after arriving from Turkey on Wednesday through the nearby Bab al-Salama crossing, the Britain-based Syrian Observatory for Human Rights said. The fighters are expected to head to frontlines nearby with the Syrian Democratic Forces (SDF), which has in recent days seized several former rebel bastions in Aleppo province. The alliance is led by the Kurdish People’s Protection Units (YPG), and its advances have alarmed Turkey, which considers the YPG a branch of the Kurdistan Workers’ Party that has waged a decades-long insurgency against Ankara.

The Observatory said the Syrian rebels were a mixture of Islamists and other fighters, with most from the Faylaq al-Sham group. It said they had arrived with weapons, though it could not provide details. “They came from (neighbouring) Idlib province and western Aleppo, entered Turkey through (Idlib’s) Atme, and reentered Syria through Bab al-Salama,” Observatory chief Rami Abdel Rahman said.—AFP