A UN peacekeeper using binoculars on an observation tower in the largely abandoned city of Quneitra
The abduction of the three observers came as the United Nations struggles to persuade the Philippines to keep its troops in the Golan force, which has been hit by growing fallout from the Syrian civil war.
At least one of the three officers from the UN Truce Supervision Organisation (Untso) seized in the early hours of Wednesday was from New Zealand, according to New Zealand media.
The UN Security Council "strongly condemned" the abduction, which it blamed on "anti-government armed elements" that looted the observation post where the peacekeepers were overrun.
The 15-member council "noted with grave concern" the growing number of seizures in the zone and expressed strong support for the peacekeepers.
"A group of unknown armed men broke into UN Observation Post 52, in the area of separation," UN peacekeeping chief Herve Ladsous told reporters.
Three unarmed Untso observers "were taken and held for approximately five hours and were released unharmed," he added, without giving the nationalities.
The officers were released after the head of the UN force intervened.
Ladsous said recent abductions of peacekeepers in the Golan had underlined "the very difficult conditions that now prevail in and around the area of operation" in the ceasefire zone.
Abductions
Twenty-one Filipino peacekeepers were abducted by Syrian rebels for five days in March.
Four more were seized by the same group this month and released on Sunday.
The Filipinos were from the UN Disengagement Observer Force, which has monitored a ceasefire between Israel and Syria in the Golan Heights since 1974.
Untso has about 170 unarmed observers based across the Middle East and one contingent helps Undof.
Undof has lost contingents from Japan and Croatia in recent months because of the growing security threat.
Some 150 troops from Fiji are set to join the ceasefire force in the coming weeks as a replacement, said a UN official, speaking on condition of anonymity.
The move has been reported by Fiji media.
Contingent could be withdrawn
Undof has cut back on patrols and other operations since the abductions, and the Philippines and other countries which provide troops to the force of about 1 000 have expressed concern.
Foreign Secretary Albert del Rosario has said his country's contingent could be withdrawn.
"We are in close contact with the troop contributors with a view to retaining their active support because they are crucial," Ladsous said. – AFP