An al-Qaeda-linked Syrian rebel group that kidnapped 45 Fijian United Nations peacekeepers on the Golan Heights has demanded removal from the global terrorism list, humanitarian aid and compensation for three militants killed in a shootout in return for the troops.

The al-Nusra Front, one of the most powerful Islamist factions fighting against President Bashar al-Assad's troops in Syria, is holding the Fijian soldiers in an unknown location.

Its militants also surrounded two Filipino units serving in the UN mission that is deployed in the buffer zone between Israel and Syria. The siege of the 70 Filipinos lasted two days, before the UN personnel reached safety.

Fiji's Brigadier-General Mosese Tikoitoga said a UN team has been sent to Syria to negotiate the captives' release.

"The rebels are not telling us where the troops are, but they continue to reassure us they are being well-looked after," Tikoitoga told media in Fiji's capital Suva. "They also told us they are ensuring that they are taken out of battle areas."

Al-Nusra published a statement online with the pictures of the Fijians along with 45 identification cards. The group said the men were "in a safe place and in good health", and accused the UN of doing nothing to help the Syrian rebels in their uprising against Assad.

Al-Nusra demands action from UN

It said the Fijians were seized in retaliation for the UN ignoring "the daily shedding of the Muslims' blood in Syria" and even colluding with Assad's army "to facilitate its movement to strike the vulnerable Muslims", according to AP.

According to Tikoitoga, al-Nusra asked for compensation for three fighters killed in clashes with the UN unit, humanitarian aid to the people of Ruta, near Damascus, and for the group to be removed from the UN's blacklist of terrorist organisations.

"We've been assured by UN headquarters that the UN will bring all its resources to bear to ensure the safe return of our soldiers," the Fijian army chief said.

The al-Nusra Front describes itself as a consisting of Sunni Muslims, who are dedicated to overthrowing Assad's regime and creating a Caliphate across all Arab countries.

During Syria's civil war the organisation uses tactics associated with terrorists, including car bomb and suicide bomb attacks, and beheadings. In 2012 the US accused al-Nusra of being a partner of Al-Qaeda. Al-Qaeda's leader in Iraq later confirmed this as accurate.