Syrian children carry placards as they call for the lifting of the siege off Madaya and Zabadani towns in Syria, in front of the offices of the U.N. headquarters in Beirut, Lebanon December 26, 2015. REUTERS/Jamal Saidi

BEIRUT (Reuters) - Besieged rebel fighters in a Syrian border town and families trapped in two Shi’ite towns in northern Syria are expected to be evacuated on Monday in the second stage of a rare, U.N.-backed deal between warring sides in Syria’s war, sources close to negotiations said.

The deal will allow scores of rebel fighters who have been holed up for months in the town of Zabadani, near the Lebanese border, to have safe passage to Beirut airport to then head for their final destination of Turkey under International Committee of the Red Cross (ICRC) auspices, the sources said.

Simultaneously, around 300 families in two besieged Shi’ite towns in the mainly rebel-held northwestern province of Idlib will be heading in a land convoy to the Turkish border from where they will then fly to Beirut.

The route via Turkey is the safest for the families as traveling through Syria would take them through Idlib where a patchwork of rebels control different areas.

The U.N. and foreign governments have tried to broker local ceasefires and safe-passage agreements as steps toward the wider goal of ending Syria’s civil war, in which more than 250,000 people have been killed in nearly five years of fighting.

Iran and Turkey, which back opposing sides in the Syrian conflict, helped bring about the local ceasefires in Zabadani and in the two villages in Idlib in September in the first phase of the deal.

The Zabadani area had been the focus of an offensive by Lebanese militant group Hezbollah and the Syrian army against insurgent groups. The area is of importance to President Bashar al-Assad because of its proximity to the Syrian capital Damascus and the Lebanese border.

Insurgent groups have in turn launched attacks on the two Shi’ite villages that intensified after most of Idlib province fell to rebels after a series of advances against the army this year.

Earlier this month Syrian government officials said they had agreed on a deal for rebel fighters to withdraw from the last insurgent-held area of the city of Homs with their weapons as part of a local ceasefire agreement.