The United Nations said Friday that more than 50 of itsstaff members have been killed, imprisoned, or gone missing in Syria. The U.N. Office for the Coordinationof Humanitarian Affairs (OCHA) said in a statement to mark International Day of Solidarity with Detained or Missing staff members that the war also had hit the Red Cross and Red Crescent as well as international and local non-governmental organizations (NGOs). "A total of 35 United Nations staff members continue to be detained or missing, the majority of whom are UNRWA (U.N.Relief and Works Agency for Palestine Refugees in the Near East) staff," the statement said. "Since the start of the crisis inSyria in March 2011, 17 U.N. 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," OCHA said. The agency said that "hundreds of medical workers" also were killed in the line of duty and that NGOs also took aheavy toll. "Since January 1, 2015 alone, credible reports indicate that at least 55 NGO staff members have been killed in Syria," OCHA said. OCHA regional humanitarian coordinator for the Syria conflict Kevin Kennedy urged all warring sides in Syria to protect humanitarian aid workers and also demanded the release of abducted U.N. 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," Kennedysaid. --SPA