Nearly 1,000 people from Syria’s Aleppo evacuated overnight after a ceasefire deal are held at an Iranian militia checkpoint outside the city, Turkey’s state-run Anadolu Agency quoted the head of the Turkish Red Crescent as saying on Wednesday.

“These people had passed the Russian check point,” Kerem Kinik told Anadolu, referring to those evacuated. “But after leaving Aleppo, they were stopped at the second point where Iranian militia was present and still they are denied passage,” he said.

Talks are still underway to allow the buses carrying civilians to move towards the rebel-held Idlib province, he added.

A ceasefire was brokered on Tuesday by Russia, Assad’s most powerful ally, and Turkey to end years of fighting in Aleppo but the planned evacuation of rebel districts stalled on Wednesday as air strikes and heavy shelling hit the city and Iran was said to have imposed new conditions on the deal.