A powerful earthquake toppled homes onto children in eastern Congo Monday, leaving an unknown number of casualties in a region already beset by war, poverty and volcanoes. UN spokesman Michel Bonnardeaux said an unknown number of people were killed or injured. Anne Edgerton, another UN spokesman in the region, said later that about a dozen injuries had been reported and no deaths could be confirmed. "Dozens of houses have collapsed, several children were buried by the roofs of their houses," Dr. Jean-Donne Owali told The Associated Press by telephone from lakeside Kalemie, Congo, 55 kilometers (35 miles) from the epicenter. "Injured people have been sent to local hospitals." He said children were brought to his clinic bleeding from wounds to the head suffered when their mud-and-thatch homes collapsed. UN spokesman Bonnardeaux said most of the casualties were struck by falling zinc and steel roofs. He added damage was reported in Kabalo, a Congolese town 300 kilometer east of Kalemie along the Lukuga River. The desperately poor region has camps for tens of thousands of refugees from wars and economic collapse in Congo and Burundi. The United States Geological Survey gave a preliminary measurement of 6.8 and located the epicenter about 10 kilometers (six miles) below the surface of Lake Tanganyika, between Congo and Tanzania. Quakes of magnitude 7 can cause widespread and heavy damage. The quake was felt as far east as Nairobi, some 1,000 kilometers (600 miles) from Lake Tanganyika. There were reports of tremors being felt as far south as the shores of Lake Victoria, some 1,100 kilometers (700 miles) away. Jacques Derieux, head of the geological survey in the eastern Congolese town of Goma said the quake was not linked to the volcanic activity that is common in the region. He placed the magnitude at closer to 6.3, still powerful enough to cause severe damage, and the location roughly in the middle of Lake Tanganyika. "Its a normal tectonic earthquake coming out of the Rift Valley," he told The Associated Press by telephone from Goma, 480 kilometers (298 miles) north of Kalemie. The Great Rift Valley runs for (4,800 kilometers) 3,000 miles between Syria and Mozambique. Celestin Kasereka Mahinda, an official at the Goma volcano observatory, said the quake could affect volcano activity. Goma's Nyiragongo volcano erupted on Jan. 18, 2002, forcing some 300,000 people to flee and destroying the homes of 120,000.