Deadly bomb and drone attacks in two different regions of Colombia were being linked to the government's war on narcotrafficking by former FARC rebels.

At least 12 police officers died in the attack on a helicopter, authorities was transporting personnel to an area in Antioquia to eradicate coca leaf crops, the raw material for cocaine.

At least five people have been killed and dozens injured after a car bomb exploded on a busy street in the western city of Cali in Colombia, according to authorities. The blast targeted the Marco Fidel Suarez Military Aviation School in the city's north and initial reports indicate 36 people were injured, police said.