A 7.4-magnitude earthquake has killed at least 169 people and injured more than 600 in Colombia, with rescuers searching for survivors.

Colombian volunteers and rescuers cleared rubble with their bare hands to search for survivors early Tuesday after the country's strongest earthquake in a decade killed at least 169 people and smashed dozens of buildings.

The 7.4-magnitude quake struck cities across Colombia's western region shortly after 7:30 am (1230 GMT) on Monday, sending panicked residents onto the streets, AFP journalists saw.

The quake killed 169 people and injured more than 600, according to an association of Colombian city mayors. The deaths were concentrated in Cali, Pereira, Manizales, and Quibdo. The mayors also reported that 165 buildings collapsed.

Colombian President Abelardo de la Espriella -- just three days after being sworn into the job -- declared a state of emergency and vowed a concerted rescue effort.