A strong earthquake early Monday killed at least four people and damaged buildings on Indonesia's Sumatra island, a witness and seismologists said. The 5.8-magnitude tremor struck just before dawn and was centered off the coast of Sumatra, Indonesia's meteorological and seismological agency said. At least four people were killed in one village in north Sumatra when two houses collapsed, a caller to local radio station el-Shinta said who identified himself as Soga. Scores of other buildings were cracked, he said. No tsunami warning was issued as a result of the quake.