A supply route for Somali refugees was cut off by an explosion, which placed another obstacle before United Nations aid agencies trying to bring supplies to thousands of Somalis who have fled Mogadishu in recent days, a UN spokesman reported Friday. The explosion occurred Thursday after the UN refugee agency UNHCR had started distributing relief to 40,000 displaced people in the region of Afgooye, 30 kilometres west of Mogadishu, dpa quoted the spokesman as saying, adding that alternative routes were insecure. According to the UN statement, UNHCR has managed to reach and provide plastic sheeting for around 1,500 families, most of whom are living outdoors under trees. The approach of the rainy season made the need for shelter more pressing, the spokesman said. The UNHCR had also managed to deliver aid to Dobley, a small town close to the Kenyan border that is struggling to cope with 4,000 displaced Somalis and an outbreak of diarrhea which has claimed the lives of six children so far. More than 200,000 Somalis have fled the capital since February to escape the violence between Ethiopian-backed government forces and Islamic insurgents.