BEIRUT - Clashes erupted between al-Qaida-linked Syrian rebels and U.N. peacekeepers in the Golan Heights on Saturday after the militants surrounded their encampment, activists and officials said, as the international organization risked being sucked further into the conflict.
Other U.N. peacekeepers were able to flee from a different encampment that that was also surrounded by rebels of the Nusra Front, al-Qaida's Syrian affiliate, they said.
The clashes came after Syrian rebel groups, including the Nusra Front, overran the Quneitra crossing -- located on the frontier between Syrian and Israeli controlled parts of the Golan Heights -- on Wednesday, seizing 44 Fijian peacekeepers.
The Nusra Front also surrounded the nearby Rwihana and Breiqa encampments, where other U.N. peacekeepers were holed up.
The gunbattle began early Saturday at the Rwihana base some 1.5 miles (2.3 kilometers) from Quneitra, where 40 Filipino peacekeepers were surrounded by Nusra fighters who were ordering them to surrender, said Rami Abdurrahman of the Britain-based Syrian Observatory for Human Rights. The Philippines' Defense Secretary Voltaire Gazmin gave a similar account but did not name the armed group.
Abdurrahman, whose information comes from a network of activists throughout Syria, said he was not aware of any fatalities among the 40 Filipino peacekeepers in the Rwihana encampment as sporadic fighting continued throughout the day. A Philippine military spokesman, Lt. Col. Ramon Zagala, also said there were no casualties.
The U.N. mission, known as UNDOF, has 1,223 troops from six countries: Fiji, India, Ireland, Nepal, Netherlands and the Philippines.
U.N. Secretary-General Ban Ki-moon strongly condemned Saturday's attack on U.N. peacekeepers' positions in the Golan Heights, in a statement released by his spokesman.
"The Secretary General demands the unconditional and immediate release of all the detained United Nations peacekeepers and calls upon all parties to cooperate fully with UNDOF to enable it to operate freely and to ensure full safety and security of its personnel and assets," the statement said.
The 35 Filipino U.N. peacekeepers at the Breiqa encampment were extracted on Saturday morning, with the assistance of Irish peacekeepers who rushed to the scene, said officials.
The Irish U.N. peacekeeper battalion, which is tasked with emergency responses, evacuated all the Filipino U.N. peacekeepers on Saturday morning, said a military official who spoke on condition that his name and country of origin not be revealed, citing army policy.
He said there was no shooting involved, and no injuries. He said that the Irish battalion also evacuated another base on Friday but provided no further details.
Gazmin confirmed that peacekeepers from his country were "extricated." The Philippine military said there were 35 Filipino troops in the encampment.
An Israeli military spokesman confirmed that a number of U.N. peacekeepers entered Israel. He spoke on condition of anonymity citing military guidelines.
It was not immediately clear which rebel group was holding the Fijian U.N. peacekeepers, although it was likely to be the Nusra Front, said Syrian activist Abdurrahman.
The Nusra Front has recently seized hostages to exchange for prisoners detained in Syria and Lebanon.
The situation of the peacekeepers, tasked with monitoring a 1974 disengagement accord between Syria and Israel, remains "very, very fluid," the U.N. secretary-general's spokesman, Stephane Dujarric, told reporters Friday at the U.N. headquarters in New York.
The U.N. said in a statement that it had received assurances from credible sources that the Fijian peacekeepers "are safe and in good health."
U.N. Secretary-General Ban Ki-moon has condemned the detention of the Fijians and called for their immediate release.
Various rebel groups have been engaged in intense fighting with the Syrian military in and near the Golan Heights.
Also Saturday, a Syrian activist released a video showing extremists from the Islamic State group opening fire and killing dozens of men stripped down to their underwear.
The men in the video were likely those who were captured after the extremists overran a Syrian airfield on Sunday; Syrian soldiers who were stuck behind front lines after the northeastern Tabqa air base fell to the Islamic State group.
The video, released by an activist who uses the name Abu Ibrahim Raqqawi, corresponded with The Associated Press reporting of the event. It matched a series of other videos that were released since Wednesday. One video showed the men being held in a concrete-floor room; another showed the men forced to march through a barren landscape in their underwear, herded like sheep. Another showed their seemingly lifeless bodies in piles on the ground.
The British-based Observatory earlier said around 120 captive government troops from Tabqa were killed near the base.
There was no immediate comment from the Syrian government.
The Islamic State group uses violence and images of violence, from mass-killings to beheadings, to instill fear in its opponents and win recruits as it seeks to expand a proto-state it has carved out in Syria and Iraq.