“The men we lost last Tuesday came from different nations, but worked together to carry out the difficult mission entrusted to them by the United Nations,” he said in a message to a memorial service held at the Headquarters of the UN Truce Supervision Organization (UNTSO) in Jerusalem. “The United Nations will be forever in their debt.”

The ceremony was held to honour the memory of Du Zhaoyu, Paeta Hess-Von Kruedener, Hans-Peter Lang and Jarno Makinen.

“Many questions surround the tragic deaths of these unarmed peacekeepers, and these must be answered,” Mr. Annan said in the message, which was delivered by Alvaro de Soto, the UN Special Coordinator for the Middle East Peace Process.

“That will not bring them back to their loved ones, but it will help us to better ensure the safety of other peacekeepers, now and in the future. Meanwhile, we must honour their work by ensuring that the death and destruction come to an end as soon as possible, and by bringing help to all those whose lives are being torn apart,” he said.

“May these brave men rest in peace. May their bereaved families find solace in the noble cause for which they died. May the nations who sent them here be proud of their men and women in uniform. And may their colleagues find, in their supreme sacrifice, the courage and determination to continue serving the cause of peace in the Middle East, and around the world.”

He noted that the four join 44 of their predecessors who gave their lives serving in UNTSO, together with 259 men and women who have died serving in the UN Interim Force in Lebanon (UNIFIL) – “including, I fear, the civilian staff member and his spouse who remain officially unaccounted for in Tyre since 17 July” – and 42 men and women who have died serving in the UN Disengagement Observer Force (UNDOF) in the Golan Heights.

“This list is a reminder of the supreme sacrifice made by people from many nations who have laid down their lives in the Middle East serving the cause of peace, under the blue flag of the United Nations.”