BEIRUT (AP) -- New video Thursday of U.N. peacekeepers held captive by Syrian rebels illustrates the sudden vulnerability of a U.N. force that had patrolled a cease-fire line between Israel and Syria without incident for nearly four decades.
The abduction of the Filipino troops -- soft targets in Syria's civil war -- also sent a worrisome signal to Israel about the lawlessness it fears along the shared frontier if Syrian President Bashar Assad is ousted.
The 21 peacekeepers were seized Wednesday near the Syrian village of Jamlah, just a mile from the Israeli-controlled Golan Heights, a plateau Israel captured from Syria in 1967.
Negotiations were under way Thursday for the release of the men, who said in videos posted online that they were being treated well.
"To our family, we hope to see you soon and we are OK here," said a peacekeeper shown in one video. He was one of three troops dressed in camouflage and blue bullet-proof vests emblazoned with the words U.N. and Philippines.
Speaking in Manila, Philippine military spokesman Col. Arnulfo Marcelo Burgos said Friday that the rebels are willing to release the peacekeepers and are asking for the International Committee of the Red Cross to escort them to a safe area.
According to Burgos, the rebels said the peacekeepers have to be removed because there is heavy fighting in the area.
He said the information came from the U.N. command.
However, a rebel spokesman seemed to suggest the hostages were also serving as human shields. If the U.N. troops are released and leave the area, the regime could kill "as many as 1,000 people," said the spokesman, who spoke via Skype and did not give his name for fear of reprisals.
The peacekeepers' abduction highlights the growing risks to U.N. staff in Syria's escalating conflict.
Fighting has spread across the country, claiming more than 70,000 lives and displacing nearly 4 million of Syria's 22 million people. There is no sign of a breakthrough for either side, though rebels have scored some recent gains on the battlefield and in the diplomatic arena.
U.N. diplomats and officials said Thursday that the capture of the peacekeepers will almost certainly lead to a re-examination of security for the U.N. force and its patrols in the field.
The U.N. 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.
For nearly four decades, the U.N. monitors helped enforce a stable truce between Israel and Syria, making it one of the most successful U.N. missions in the world, said Timor Goksel, a Beirut-based former senior U.N. official in the region.
The force has an office in Damascus and staffs observation posts along the armistice line.
Goksel, who works for the Al-Monitor news website, said the observers are "soft targets" in Syria's increasingly brutal civil war. Up to now they were "never challenged by anybody in Syria," he added.
The monitors' success may have been linked to a decision by Assad and his father and predecessor, Hafez Assad, to comply with the armistice deal, including limits on military hardware allowed near the cease-fire line.
Moshe Maoz, an Israeli expert on Syria, said the U.N. mission's success was largely due to the Assads' decision to abide by the truce.
"When you are dealing with an army that follows orders, it is one thing," Maoz said. "Now you have different groups. They do not recognize international law and have no respect for any law or international morals. They are terrorist groups that know no bounds."
An Israeli official said that if UNDOF were to halt operations, it would be a "bad thing for peace." He spoke on condition of anonymity because he was not authorized to discuss the diplomatically sensitive issue with the media.
Israel has said it's trying to keep out of the Syria conflict, but is watching the disintegration of the country with growing concern.
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.
The U.N. 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, about a mile from the armistice line.