Federal forces will take control of security in 13 municipalities in the state of Guerrero in an ongoing investigation in the fate of 43 missing students, authorities announced late Sunday.

National Security Commissioner, Monte Alejandro Rubido García, said that the decommission of local police officers was necessary as the investigation into the disappearance of the male students late last month from a rural teachers college showed potential links between organized crime and the local police in the municipalities.

Twelve of the municipalities are located in the state of Guerrero, where police opened fire during a Sept. 26 student protest in Iguala, resulting in six deaths and the missing students. The other municipality, the tourist city of Ixtapan de La Sal in the state of Mexico, is 62 miles (100 km) from Iguala.

Attorney General Jesus Murillo Karam confirmed Sunday that 36 local police officers had already been arrested in Iguala and Cocula, a neighboring municipality. Both cities have already been disarmed and are under the control of federal forces. Karam added that 17 members of the Guerreros Unidos, or United Warriors, a regional drug cartel, have also been detained, including the suspected leader, Sidronio Casarrubias Salgado.

Mexican authorities are also searching for Iguala’s Mayor José Luis Abarca, who was impreached by the Guerrero state Congress, and the city's police chief. It is believed that both are linked to Guerrero Unidos and collaborated with local police in the disappearance of the students. 

  Police continue to search for evidence more than three weeks after the students disappeared in a case that has garnered international attention.

Five mass graves containing 28 sets of human remains were discovered just outside of Iguala two weeks ago, raising the specter that they were at least some of the students. Karam, however, confirmed last week that thre remains did not belong to the missing youths. A team of Mexican and Argentinian forensic experts is now investigating the remains from another set of graves also located outside Iguala.

As more corpses and graves are discovered, Mexican indignation continues to rise.

Demonstrations and marches have been organized in Guerrero almost every day since the students disappeared last month.

Last week, classmates of the students and teachers from Guerrero threw rocks and set fire to Chilpancingo's City Hall, Guerrero’s capital. And thousands of demonstrators marched in the streets of Acapulco demanding that authorities return students alive.

Students from several national universities plan a night march in downtown Mexico City on Wednesday, in support of the missing students’ relatives.

Anadolu Agency