GENEVA, June 1 (Xinhua) -- Human traffickers in Libya reportedly killed more than a dozen people and wounded many others after some 200 Eritrean, Ethiopians, and Somalis -- held captive -- attempted to escape, the UN refugee agency UNHCR said Friday.

"According to the survivors, people were shot while trying to escape and during attempts to recapture them," UNHCR spokesperson William Spindler said at a UN briefing here.

He said the survivors spoke of torture abuse and exploitation at the hands of traffickers, some held in captivity for up to three years

The incident happened on May 23, in Bani Walid, some 180 km southeast of the capital Tripoli.

According to the survivors, people were shot while trying to escape and during attempts to recapture them.

"This latest deadly incident demonstrates, once again, the huge challenge of providing protection to refugees in Libya, where many people fleeing war and often perish at sea while searching for safety in Europe," said Spindler.

The local Libyan authorities have transferred 140 people who managed to escape from the traffickers to an official detention center in Gaser Ben Gashir, 28 km south of Tripoli.

"In Gaser Ben Gashir, UNHCR has distributed relief items, providing psychosocial support and undertaking protection screening to identify and register those in need of international protection," said Spindler.

Following this, UNHCR has identified many unaccompanied children among the group.

"We are currently identifying the most vulnerable cases to find appropriate solutions for them. UNHCR believes that many refugees and migrants may still be hiding or in captivity in or near Bani Walid," Spindler said.

UNHCR said it continues to call on resettlement countries and the international community to step forward, open more resettlement places and identify ways to protect vulnerable refugees in Libya and beyond that need international protection.