* Whereabouts of 44 Fijian peacekeepers unknown
* More than 70 Philippine troops safe after "greatest escape"
* Bases on Syria-Israel frontier came under attack on Thursday
* Syria and Israel helped get troops back, U.N. says
* Militants say Fijians are in good health
By Louis Charbonneau and Avi Ohayon
UNITED NATIONS/EIN ZIVAN, Golan Heights, Aug 31 (Reuters) - The head of the Fijian army said on Sunday negotiations for the release of 44 soldiers seized by an al Qaeda-linked group on the Syrian side of the Golan Heights were being pursued but he worried there had been no word on where his men are being held.
The U.N. peacekeepers from Fiji were detained by Islamist militants on Thursday, one of several groups attacked in the volatile frontier between Syria and Israel.
The United Nations and Manila said on Sunday all of more than 70 Philippine troops trapped by Islamists in a different area of the frontier were now safe, but it is still not known where the Fijians are being held.
"We still at this stage cannot confirm the exact location of our troops. We are continuing negotiations at all levels," Fijian Army Commander Brigadier General Mosese Tikoitoga told a media conference in Fiji on Sunday.
He said they had been assured that the men were being treated well and had come to no harm, he said.
"However, we are still very concerned that we cannot confirm at this stage their exact location, whether they are still in Syria or whether they have been moved to neighbouring countries," Tikoitoga said.
The Fijian and Philippine troops are serving with UNDOF in the Golan Heights, a strategic plateau captured by Israel in the 1967 Middle East War.
Syria and Israel technically remain at war and UNDOF monitors the area of separation, a narrow strip of land running about 70 km (45 miles) from Mount Hermon on the Lebanese border to the Yarmouk River frontier with Jordan.
The United Nations said earlier on Sunday that 40 Philippine troops had been moved to safety during a ceasefire agreed with "armed elements" in the area shortly after midnight local time.
In Manila, General Gregorio Catapang, the Philippines' armed forces chief, told a news conference that Israel and Syria helped in what was the "greatest escape" of Filipino troops after engaging about 100 Islamist militants surrounding them in a seven-hour firefight. The troops escaped in the middle of the night while the rebels were sleeping, he said.
"This attack prompted UNDOF to reposition our troops to a more secure position within the mission area," Catapang said.
He said all Philippine troops from two camps, known as Position 68 and Position 69, in the area had been moved to a third location, known as Camp Ziuoani.
On Saturday, 32 Philippine peacekeepers were rescued from Islamists who fired on Position 69 and trapped them for two days, the United Nations said. Catapang said Irish UNDOF troops helped in the rescue. It was not known if any rebels were killed or wounded in the operation.
But later that day, U.N. diplomatic sources said militants had reinforced their siege of the other 40 Philippine peacekeepers still trapped at Position 68.
The U.N. media office said in a statement that "shortly after midnight local time on 31 August, during a ceasefire agreed with the armed elements, all the 40 Filipino peacekeepers from UN Position 68 left the position. The 40 peacekeepers arrived in a safe location one hour later."
Earlier on Saturday, a Reuters cameraman spotted 11 U.N. armoured vehicles returning to their base in Israeli-controlled territory about 12 hours after the peacekeepers came under fire at around 6 a.m. (0300 GMT).
The 44 UNDOF peacekeepers from Fiji were detained by militants 8 km (5 miles) away from the Philippine troops.
A commander with the Islamist Nusra Front, a group linked to al Qaeda, told Reuters the Fijian peacekeepers had been detained because UNDOF was aiding the government of President Bashar al-Assad and had ignored the suffering of the Syrian people.
Rebels of al Qaeda-linked Nusra Front have been battling the Syrian army in the area and have wrested control of the border crossing at Quneitra, which is operated by the United Nations.
UNDOF has been deployed "since 1974 to ensure the safety and protection of the borders with (Israel), the usurper of the lands of the Muslims, at the same time it completely ignored the daily shedding of the Muslims' blood on the other side of the border", part of a Nusra Twitter message said.
It said the Fijian troops were being treated well and were in good health.
A U.N. official said a number of UNDOF contingents participated in the rescue on Saturday, assisted by Israeli and Syrian forces.
UNDOF has 1,223 peacekeepers in the zone from six countries: Fiji, India, Ireland, Nepal, the Netherlands and the Philippines.
The United Nations said this week the Philippines had decided to pull out of UNDOF and from a U.N. force in Liberia, which is struggling with an outbreak of the deadly Ebola virus.
Austria, Japan and Croatia have all pulled their troops out of UNDOF due to the deteriorating security situation and spillover from the Syrian war. (Additional reporting by Lincoln Feast and Matt Siegel in Sydney, Mariam Karouny in Beirut, Jeffrey Heller in Jerusalem and Rosemarie Francisco and Manuel Mogato in Manila; Editing by Paul Tait)