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.

A Black Hawk was attacked by cocaine-trafficking group, officials said, the latest in an escalating series of drone attacks against security forces.

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