At least 20 people were killed and dozens of buildings collapsed in cities across western Colombia on Monday after a powerful 7.4-magnitude earthquake struck the South American nation, trapping residents under debris, leaving more injured and forcing people to evacuate their homes as far as the capital of Bogota.

Local officials confirmed that at least 18 people had been killed in the city of Pereira and two in the city of Manizales.

The epicentre was in San José Del Palmar, the U.S. Geological Survey and Colombia's counterpart reported, referring to a municipality in the Choco region of about 4,800 people and located about 400 kilometres west of Colombia's capital, Bogota. The USGS said it struck at a depth of 107 kilometres.