The United Nations refugee agency expressed deep concern on Friday at reports of soldiers taking hundreds of people away from displacement camps in the Tigray region of Ethiopia earlier this week, saying such sites should be a safe haven.

A doctor and 3 aid workers told Reuters this week that Ethiopian and Eritrean soldiers forcibly arrested over 500 young men and women from 4 camps for displaced people in the town of Shire in the northern region on Monday night.

Babar Baloch, spokesman of the U.N. High Commissioner for Refugees (UNHCR), told a Geneva news briefing: “We reiterate our call on all parties to ensure the protection of civilians including the forcibly displaced. It is crucial that all parties to the conflict recognize the civilian and humanitarian character of the displacement sites.”

Baloch said some had been freed after UNHCR raised the matter with Ethiopian authorities, but provided no figure.

He added that “the situation is traumatic and distressing not only for the relatives of the missing but for all the displaced communities residing in Shire.”

It was not immediately clear where the remaining youth were being detained, Baloch said.

According to the latest report by the U.N. Office for the Coordination of Humanitarian Affairs, thousands of people have been killed since the conflict broke out, 2 million have been forced from their homes and 91% of the population of about six million are in need of aid.