Security officials say federal police have taken control of 13 municipalities in southern Mexico where local police are suspected of possible links to organized crime and the case of 43 missing students.

National Security Commissioner Monte Alejandro Rubido says that during the investigation into the disappearance of the students three weeks ago authorities found "irregularities" and "presumed links to organized crime" in the municipal police forces.

The locales all are within a 125-mile (200-kilometer) radius of Iguala, where the students from a rural teachers' college disappeared after a confrontation with police. Both the mayor and police chief of Iguala are fugitives and accused of links to the local drug cartel, Guerrero Unidos, believed to have worked with police in disappearing the students.