Beirut: Warring sides in Syria have reached an agreement under UN supervision over the fate of two villages in the northwest and a town near the Lebanese border, sources familiar with the talks said on Thursday, as a ceasefire in the areas held.

The deal included the withdrawal of rebel fighters holed up in the mostly regime-held area near Lebanon, and the evacuation of civilians from two Shiite villages under rebel siege in Idlib province in northwest Syria, the sources said.

It would be implemented within six months, during which time there would be an extended ceasefire in the areas. Evacuation of wounded from both sides would begin on Friday.

Meanwhile, US-trained rebels who recently returned to Syria said on Wednesday they have lost contact with one of their officers and that they are investigating reports he defected and handed over his weapons to Al Qaida’s branch in the country.

The allegations come only days after the group of about 70 rebels returned to Syria after training in Turkey as part of the US programme to train and equip rebels to take part in the fight against the Daesh group.

If confirmed, defection among the ranks of US trained rebels would be an embarrassment to the programme, which has already been criticised as offering too little too late and failing to provide enough protection for those trained rebels once inside Syria.

US officials have begun an overhaul of the efforts, including suggesting that the newly trained fighters operate as the New Syrian Forces alongside Syrian Kurds, Arab and other anti-Daesh forces.