Police officers stand behind a seized weapon at the police station in Necocli, Colombia, March 11, 2015.
Police officers stand behind a seized weapon at the police station in Necocli, Colombia, March 11, 2015.

BOGOTA - Twelve members of Colombia's top crime gang, the Usuga Clan, were killed during a confrontation with the armed forces in the northwestern province of Antioquia, the defense minister said on Tuesday.

Troops confiscated arms and destroyed five encampments belonging to the group, which is allegedly involved in international drug trafficking, Defense Minister Luis Carlos Villegas told journalists.

The national police said that no government troops were injured.

The government has stepped up its offensive against the Usuga Clan in a bid to capture its leader Dario Antonio Usuga, known as Otoniel. The United States is offering a $5 million reward for information on him.

Crime gangs, often comprised of ex-paramilitaries who did not demobilize during a peace process a decade ago, are considered the South American country's most challenging security threat.