More than 50 UN staff members have been killed, imprisoned or gone missing in war-wracked Syria, the UN Office for the Coordination of Humanitarian Affairs said on Friday.
In a statement to mark International Day of Solidarity with Detained or Missing staff members, OCHA said the war had also hit the Red Cross and Red Crescent as well as international and local NGOs.
"A total of 35 United Nations staff members continue to be detained or missing, the majority of whom are UNRWA staff," it said, referring to the agency dealing with Palestinian refugees.
"Since the start of the crisis in Syria in March 2011, 17 UN staff members, 53 Syrian Arab Red Crescent staff members and volunteers, and eight Palestinian Red Crescent Society staff members and volunteers have lost their lives," the agency said.
It said that "hundreds of medical workers" were also killed in the line of duty and that NGOs also took a heavy toll.
"Since 1 January 2015 alone, credible reports indicate that at least 55 NGO staff members have been killed in Syria," OCHA said.
The agency's regional humanitarian coordinator for the Syria conflict, Kevin Kennedy, spoke of a "shocking and bleak reality".
Kennedy urged all the warring sides in Syria to protect humanitarian aid workers and also demanded the release of abducted UN staff.
"We call for the unconditional and immediate release of those colleagues who continue to remain in custody, and for parties to the conflict to reveal the fate of those still missing," he said.