The United Nations hopes to retrieve 21 peacekeepers from Syrian rebels on Saturday during a two-hour truce agreed to by Syrian troops and opposition groups after a release bid was abandoned on Friday, the United Nations and an opposition group said.

U.N. peacekeeping chief Herve Ladsous said the Filipino peacekeepers were being held in the basements of four houses in the village of Jamla, near the Israeli-occupied Golan Heights, which was being subjected to intense shelling by Syrian troops.

The peacekeepers - part of the U.N. Disengagement Observer Force, which has been monitoring a ceasefire line between Syria and Israel in the Golan Heights since 1974 - were seized by the Martyrs of Yarmouk rebel brigade on Wednesday.

The Syrian Observatory for Human Rights, a Britain-based monitoring group, said the warring parties in Syria were aiming for a ceasefire in the area between so the peacekeepers could be released.