New Delhi, Dec. 17 -- Colombian police said Tuesday that two officers were killed in the southwestern city of Cali in an attack by the National Liberation Army, a rebel group that has increasingly targeted authorities in what it says is an effort to show its opposition to the U.S. military buildup in the Caribbean.

Police said the officers were patrolling a neighborhood on motorcycles when they were hit by a roadside bomb. The officers were taken to a nearby hospital but did not survive their injuries.

The National Liberation Army, also known by its Spanish acronym ELN, launched a 72-hour "armed strike" on Sunday to protest the U.S. military buildup in the Caribbean.

During these armed strikes, schools and businesses are forced to clos...