In southern Mexico, federal police have taken control of 13 municipalities where local police are suspected of organized crime links and a possible connection to the 43 missing students, according to a top official.
The municipalities are all within a 125-mile radius of Iguala, the town where the students from a rural teachers' college disappeared more than three weeks ago after a confrontation with police. Among them are the tourist destinations of Taxco and Ixtapan de la Sal.
Federal police have assumed control of public security in the municipalities.
National Security Commissioner Monte Alejandro Rubido said Sunday night that authorities investigating the disappearance of the students found "irregularities" and "presumed links to organized crime" in these 13 municipal police forces.
Federal officials had already disarmed Iguala and Cocula's local police and arrested 36 officers. Iguala's mayor and police chief are fugitives, accused of organized crime links and of working with local police in the students' disappearance.
The missing students has outraged Mexicans, with thousands of protesters marching recently in Mexico City, Acapulco and elsewhere to demand their safe return.
- Mexico: Protests, Demands For Missing Students
- Survivor of Mexico Student Massacre: It Was Terrifying
- Mexico Massacre: Did Cops In Guerrero Conspire To Kill Missing Students?
--The Associated Press