Eight suspected members of the Los Rastrojos gang were arrested in Bahia Solano and Nuqui, two cities located in the northwestern Colombian province of Choco, the navy said Sunday.
Pacho Valois, the gang's suspected leader, was among those arrested.
Attorney General's Office and navy personnel carried out the operation that led to the arrests in urban and rural sections of the cities.
The suspects were involved in drug trafficking, staging attacks on the security forces and running extortion rackets targeting business owners, officials said.
Authorities seized 107.5 kilos of cocaine, 1.6 tons of marijuana, arms and ammunition from the Los Rastrojos cell operating in the two cities over the past 18 months, the navy said.
The gang's operations have been dismantled in Nuqui and Bahia Solano, officials said.
Leonardo Fabio Barrera Santos, who ran the gang's finances in the northeastern city of Puerto Santander, was arrested in a separate operation, the National Police said.
Los Rastrojos is one of a number of groups founded by veterans of the defunct United Self-Defense Forces of Colombia, or AUC, militia federation.
Los Rastrojos and the other AUC successor groups, such as Los Paisas and Nueva Generacion, are responsible for a good deal of the criminal activity in Colombia, officials say. EFE