UNITED NATIONS - A group of armed fighters linked to the Syrian opposition detained more than 20 U.N. peacekeepers Wednesday in the increasingly volatile zone separating Israeli and Syrian troops on the Golan Heights.
The U.N. 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 Feb. 25 announcement that a member of the peacekeeping force, known as UNDOF, was unaccounted for. The U.N. said the peacekeeping member, who has not been identified, is still missing.
Russia's U.N. Ambassador Vitaly Churkin, the current Security Council president, said talks are under way between U.N. officials from the peacekeeping force, known as UNDOF, and the captors.
U.N. 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, Churkin said.
"There was no fighting, according to his briefing to us," Churkin said. "My understanding is that they took over the trucks in which the UNDOF personnel was moving around."
U.N. deputy spokesman Eduardo del Buey said about 20 U.N. 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 U.N. 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 left 11 fighters and 19 regime forces dead.
A man identified as Abu Qaed al-Faleh, spokesman for the Martyrs of Yarmouk Brigades, announces the group is holding the peacekeepers until Syrian President Bashar Assad's forces withdraw from Jamleh.
"They will not be released until after Bashar Assad's forces withdraw from the village of Jamlah bordering Israel," the man said.
Churkin said the capture of the peacekeepers "is particularly unacceptable and bizarre (because) UNDOF are unarmed and they have nothing to do with the situation in Syria."
"They are there on a completely different mission so there is no reason at all under any circumstances, any kind of sick imagination to try to harm those people," he said.
Churkin urged countries with influence on the Syrian opposition to use it to help free the peacekeepers.
The U.N. force was established in 1974 following the 1973 Yom Kippur war to monitor the disengagement of Israeli and Syrian forces and maintain the cease-fire. Israel captured the Golan Heights from Syria in 1967 and Syria wants the land returned in exchange for peace.
U.N. Secretary-General Ban Ki-moon has warned of escalating military activity along the Israeli-Syrian border as a result of the intensifying Syrian conflict, which began in 2011 and has cost more than 70,000 lives.
In December, Ban accused the Syrian government of serious violations of the 1974 separation agreement and called on both countries to halt firing across the cease-fire line. He cited numerous clashes between Syrian security forces and opposition fighters in the disengagement zone.
In response, he said, UNDOF has adopted a number of security measures.
Associated Press Writer Zeina Karam contributed to this report from Beirut