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.
Rebels said 10 people have died in regime shelling of Jamlah and nearby villages in recent days. Fighting continued Thursday, according to activists.
The rebels and Syrian opposition officials have sent conflicting messages about the peacekeepers' release.
Immediately after their seizure, one of the rebels said the U.N. troops would be held until regime forces leave Jamlah.
On Thursday, however, a spokesman for the captors expressed concern about more regime attacks on the area if the hostages are freed, suggesting release was not imminent.
A member of Syria's political opposition in exile, Khaled Saleh, said the rebels would deliver the U.N. troops to safety in Jordan as soon as the regime halts airstrikes in the area and a transfer is deemed safe.
In two amateur videos posted Thursday, men who appeared to be captive U.N. troops made similar statements, though it was not clear to what extent they had been coerced to do so.
"We, the U.N. personnel here, are safe, and the Free Syrian Army are treating us good," one of three peacekeepers shown in the video said in halting English. "We cannot go home because the government of (President Bashar) Assad do not stop the bombing."
In another video, six men, presumably peacekeepers, are shown. One man, who identifies himself as a captain, says the U.N. force encountered bombings and artillery, and civilians in the area "helped us for our safety."
The videos appear in line with AP reporting of the incident.
The U.N. Security Council, which has demanded the peacekeepers' immediate and unconditional release, scheduled a closed meeting Friday with U.N. peacekeeping chief Herve Ladsous.
"As far as we know they are safe," Ladsous told a group of reporters Thursday. "But of course we demand the immediate freedom and the ability for UNDOF to carry out its mandate in the area of the Golan."
In Washington, State Department spokeswoman Victoria Nuland called the men's continued detention "absolutely unacceptable."
The Britain-based Syrian Observatory for Human Rights, an activist group, said negotiations were under way between the rebels, the Arab League and U.N. officials on handing over the peacekeepers. As part of the negotiations, the rebels were demanding that the regime withdraw from the area, end shelling attacks and allow refugees to return, the Observatory said.
Meanwhile, Nuland said Assad's forces have bombarded opposition-held neighborhoods in the central city of Homs over the last 24 hours and cited reports that regime forces were amassed outside of the city "for what looks to be an all-out assault on rebel holdouts."
Associated Press writers Bassem Mroue in Beirut, Aron Heller in Jerusalem, Edith M. Lederer at the United Nations and Bradley S. Klapper in Washington contributed to this report.
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