The number of missing remained unknown Tuesday after a flood and mudslide killed at least 69 people and injured 40 in north-western Colombia, authorities said, according to dpa. The ombudsman's office said the authorities were trying "to verify reports that speak of a little more than 150 people missing" after the disaster, which happened in the early hours of Monday. A swollen stream overflowed with mud and debris in the rural area and swept away many victims while they were asleep. "The difficulty in this procedure is in finding people who are missing, because the stream has quite a large volume of water, so an alert has been declared for every municipality so they keep watch in case a body flows by," Sergio Fajardo, governor of the Antioquia province, told the Caracol radio network. Cesar Urena, head of the Red Cross's National Relief department, said 69 bodies have been found. The identification process is to take place in the Antioquia capital Medellin. Only 18 people have been identified so far, and the authorities are cautious about the number of missing people since some of them may already have been found dead. Rescue teams are cooperating with the Red Cross, Civil Defence, police and the Army. The disaster occurred in the municipality of Salgar in the province of Antioquia about 560 kilometres north-west of Bogota. The Liboriana stream, which goes through a rural area with about 800 residents known as Las Margaritas, spilled over its banks as a result of recent heavy rain. Meteorologists have warned that heavy rain is expected to continue in the coming days.