Arrangements have been made with all parties for the release of 21 UN peacekeepers held captive by Syrian rebels, although the operation was delayed as darkness fell Friday, the United Nations said

A team of peacekeepers was sent Friday to bring back their colleagues, who are being held in the village of Jamlah near the Israeli-controlled Golan Heights, said Josephine Guerrero, a spokeswoman for the UN Peacekeeping Department.

Because of the late hour and darkness "it was considered unsafe to continue the operation" but efforts will resume Saturday, she said.

The captive troops, all Filipinos, are from a peacekeeping mission that had monitored a cease-fire line between Israel and Syria without incident for nearly four decades. Their abduction Wednesday illustrated the sudden vulnerability of the UN mission amid spillover from Syria's civil war. It sent a worrisome signal to Israel, which fears lawlessness along the shared frontier if Syrian President Bashar Assad is ousted.

Held in basements

Earlier, UN peacekeeping chief Herve Ladsous told reporters that the Filipinos are being held in the basements of four or five houses in Jamlah.

The peacekeepers are apparently safe, he said, but the village "is subjected to intense shelling by the Syrian armed forces."

"As of now, there is perhaps a hope — but I have to be extremely cautious because it is not done yet — but there is the possibility that a cease-fire of a few hours can intervene which would allow for our people to be released," he said after briefing the UN Security Council.

"If that were to happen, as we all hope," Ladsous said, "we would strongly expect that there not be retaliatory action by the Syrian armed forces over the village and its civilian population after our people have left."

Four-vehicle convoy intercepted

The peacekeepers' four-vehicle convoy was intercepted Wednesday by rebels from a group calling itself the Martyrs of the Yarmouk Brigades. The convoy was stopped on the outskirts of Jamlah.

Rebels said 10 people have died in regime shelling of Jamlah and nearby villages in recent days. Fighting continued Thursday, according to activists.

Syria's UN Ambassador Bashar Ja'afari denied that government forces were shelling Jamlah, but he said they were involved in military activity in the suburbs "where the armed groups are concentrated."

He said Syria has three goals: To ensure the safe release of the peacekeepers; guarantee the safety of the inhabitants of Jamlah and other villages; and "get these armed groups, terrorists, out of there." He said Syrian soldiers are willing to risk their lives to see the safe release of the peacekeepers.

The capture of the peacekeepers came a week after the announcement that a member of their mission is missing.

Ladsous said that in light of the volatile situation in the area, the United Nations has vacated two positions which were particularly exposed to gunfire, one at the extreme south of area of separation.

"In a wider sense, of course we are looking very closely at the `modus operendi' of the mission in the situation it is facing," he said.

The UN monitoring mission, known as UNDOF, was set up in 1974, seven years after Israel captured the Golan and a year after it managed to push back Syrian troops trying to recapture the territory in another regional war.

UN has helped enforce truce

For nearly four decades, the UN monitors helped enforce a stable truce between Israel and Syria.

But in recent months, Syrian mortars overshooting their target have repeatedly hit the Israeli-controlled Golan. In Israel's most direct involvement so far, Israeli warplanes struck inside Syria in January, according to U.S. officials who said the target was a convoy carrying anti-aircraft weapons bound for Hezbollah, a Lebanese militia allied with Assad and Iran.

UN spokesman Martin Nesirky said "the mission in the Golan needs to review its security arrangements and it has been doing that."

He said the mission has been looking at different scenarios and arrangements on how to operate "in these new rather difficult and challenging circumstances."

One change that has already been made is the elimination of night patrols, Nesirky said.