A trio of blue berets serving with the United Nations Disengagement Observer Force in the Golan Heights were detained Sunday at the Israeli border, accused of carrying bottles of liquid cocaine.

"We are looking into the matter to ascertain the circumstances and find out more details," a UN Peacekeeping spokesperson told AFP. "Including with the view to investigate this matter thoroughly."

The detained soldiers were serving in the Fiji Battalion of the UN force, authorities in Suva have confirmed.

Major-General Ro Jone Kalouniwai, commander of Fiji's military, said in a Monday statement that the troops had been returning from leave in Jordan when they were stopped at the frontier on "allegations of drugs smuggling".

"All soldiers concerned will be dealt with in accordance with the military law and laws of Fiji," he said, promising "zero tolerance" for "any criminal activities".

Fijian authorities are said to be liaising with their Israeli counterparts on the matter and will send an investigative team to the region.

Israel's Tax Authority said that "three UN employees, serving on the Syrian border" were stopped during a routine inspection at the Jordan River Crossing -- also known as Sheikh Hussein Bridge -- on Sunday.

Suspicions were raised about perfume-making kits that members of the group were allegedly carrying and "which included bottles with liquid cocaine".

Israel captured the Golan Heights from Syria during the 1967 Six-Day War.

In 1974, a UN force was dispatched to a buffer zone and tasked with monitoring a ceasefire.

Today, the force includes about 1,000 troops from a dozen nations, including Fiji, Argentina, Ireland and Nepal.