Hundreds of families of Islamic State militants and some injured fighters are expected to leave rebel-held areas of southern Damascus under a U.N.-brokered deal, a monitoring group said on Thursday.

Safe passage would be given from the Palestinian refugee camp of Yarmouk on the outskirts of Syrian capital and neighboring Hajar al Aswad, said Rami Abdulraham, head of the British-based Syrian Observatory for Human Rights.

The families and some fighters will be taken to Raqqa in northern Syria, the stronghold of the militant Sunni Islamist group, and other Islamic State-controlled areas over several months, eventually ending the group's presence near Damascus.

Islamic State has had a significant foothold in Hajar al Aswad, just a few kilometers from President Bashar Assad's seat of power.

Syria's minister for national reconciliation, Ali Haidar, told Reuters that efforts were underway to get militants out of the Yarmouk camp but gave no details.

A U.N. spokesman told reporters in New York: "The U.N. is an observer to the agreement concerning Yarmouk, but not part of it, which we understand should come into effect in the coming few days."

Several local cease-fires and safe-passage agreements have been concluded elsewhere in Syria recently. One, brokered with support from Iran and Turkey, halted fighting in the town of Zabadani on the Lebanese border, and in two villages in northwestern Syria.

A deal was also reached in the last rebel-held district of the Syrian city of Homs that allowed rebels and their families to leave the besieged area. The U.N. said the agreement could help pave the way for a nationwide truce.