On 29 May 1948, UN Security Council Resolution 50 (1948), called for a cessation of hostilities in Palestine and decided that the truce should be supervised by the Bernadotte with the assistance of a group of military observers. The first group of military observers, which later became known as UNTSO, arrived in the region in June 1948, when the Security Council threatened Chapter VII intervention. To enforce the first of two truces, lasting four weeks, the United Nations then established an observer formation, with members drawn from Belgium, France, and the United States. On 6 July the UN observers had their first casualty with the death of the French Observer Commandant Rene de Labarriere, who was wounded near the Afoula area and later died in the Jewish Hospital at Afoula. He was wounded while investigating an alleged violation of the truce provisions by Jewish forces.