A group of armed fighters linked to the Syrian opposition has detained more than 20 UN peacekeepers in the increasingly volatile zone separating Israeli and Syrian troops on the Golan Heights.
The UN Security Council demanded their immediate and unconditional release.
The capture of the peacekeepers marked a new escalation in the spillover of Syria's civil war, now entering its third year. It followed the February 25 announcement that a member of the peacekeeping force, known as UNDOF, was unaccounted for. The UN said the peacekeeping member, who has not been identified, is still missing.
Russia's UN Ambassador Vitaly Churkin, the current Security Council president, said talks are under way between UN officials from the peacekeeping force, known as UNDOF, and the captors.
UN peacekeeping chief Herve Ladsous, who briefed the council behind closed doors, identified the captors as being from a group associated with the Syrian armed opposition, Mr Churkin said.
"There was no fighting, according to his briefing to us," Mr Churkin said. "My understanding is that they took over the trucks in which the UNDOF personnel was moving around."
UN deputy spokesman Eduardo del Buey said about 20 UN observers were on a regular supply mission when they were stopped by approximately 30 armed fighters near an observation post that was damaged in heavy combat last weekend and had been evacuated.
A video posted online by activists showed a group of armed rebels standing around at least three white UN vehicles with the words UNDOF on them, allegedly in the village of Jamleh bordering Israel in Daraa province.
The video, circulated by the Syrian Observatory for Human Rights, said the peacekeepers being held by the rebels are 20 Filipinos.
It accuses the peacekeepers of assisting the Syrian regime to redeploy in an area near the Golan that the fighters had seized a few days ago in battles that left 11 fighters and 19 regime forces dead.