A car bomb and an attack on a police helicopter in Colombia have killed at least 17 people, including police officers.

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 18 people have been killed and dozens wounded in two separate attacks in Colombia, deepening the country's most serious security crisis in decades. Six people died and more than 60 were injured after a car bomb exploded on a busy street in the western city of Cali in Colombia, according to authorities.