Attacks in the country's third largest city Cali and several nearby communities were directed at police stations and other municipal buildings, but also at civilian targets, says police chief Carlos Fernando Triana to the local radio station La FM.
Two police officers have been killed and a number of members of the public have also been killed, he says.
At least seven people are dead and 28 injured, according to the police.
According to the police, the perpetrators have used car bombs, motorcycle bombs, gunfire and possibly drones.
We thought it was an earthquake, says Luz Amparo, who was at home when a powerful explosion shook her neighborhood, to AFP.
It is still unclear who is behind the attacks, but it is known that breakaway factions from the Farc guerrilla are active in the area. The police chief suggests that the attacks may be linked to the third anniversary of the murder of a guerrilla leader.
The attacks come just days after the attempted murder of presidential candidate Miguel Uribe, who was shot in the head when he spoke in a park in Colombia's capital Bogotá on Saturday.
