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.

Two attacks by dissident guerrilla groups killed 18 people and wounded dozens in Colombia on Thursday, authorities said, as a truck bomb struck Cali and a drone downed a police helicopter at a