U.N. officials shuttled along the rocky frontier between Syria and the Zionist entity-occupied Golan Heights on Friday, trying to establish the whereabouts of 43 United Nations peacekeepers seized by terrorist gunmen inside Syria.

About 80 U.N. soldiers from the Philippines, all of whom serve with UNDOF, a U.N. force that has monitored the disengagement zone between the Zionist entity and Syria since the 1973 Arab-Zionist war, remain locked down in two camps on the Syrian side of the frontier, military officers in the Philippines said.

Zionist soldiers, including some redeployed from Gaza, prevented anyone moving too close to the border.

From a lookout point on the Zionist-controlled side, with views across southeastern Syria, Al-Nusra Front gunmen could be seen moving on motorbikes and in pick-up trucks, while further away the Syrian army battled opposition forces.

It is the third time in two years that UNDOF troops have been seized on the Syrian side of the demarcation zone.

In both previous cases those seized were released within days, U.N. officials said. But the situation appears to be more precarious this time.

In Manila, a senior officer said the Filipino troops holed up on the Syrian side were well-armed, well-trained and had no intention of surrendering to the gunmen.

The Golan is a strategic plateau captured by the Zionist entity in the 1967.

UNDOF monitors the area of separation, a narrow strip of land running about 45 miles (70 km) from Mount Hermon on the Lebanese border to the Yarmouk River frontier with Jordan.

Philippine army officials said hope remained for an easing of the situation despite the standoff with the Philippine peacekeepers and the lack of knowledge of the precise whereabouts of the Fijians.

The Philippine Foreign Ministry called on the United Nations "to exert every effort to ensure the safety and security of all peacekeepers in UNDOF", which consists of Indian, Nepalese, Irish and Dutch troops, as well as the Fijians and Filipinos.