Mexican federal agents have disarmed all police in the city of Iguala and taken over security. Local officers are alleged to have conspired with a criminal gang to kill 43 missing students, with a mass grave discovered.
A newly-created preventative unit of Mexico's federal police moved into the southern city of Iguala on Monday, disarming its entire police force. The federal agents have been tasked with keeping law and order in the city and helping in the search for 43 missing students.
Army trucks and convoys of the paramilitary-like gendarmerie police force are guarding the streets of Iguala, a city of 140,000 residents, while soldiers are manning checkpoints.
The southern city's police force stands accused of colluding with a criminal gang in violence that left the students missing nearly two weeks ago. The students had traveled to the area to protest over teachers' rights, but were shot at by police after they allegedly hijacked a number of buses.
Six people were left dead in the shootout, with dozens wounded and 43 reported missing. Investigators reported the existence of a video showing police taking away several of the student protesters.
Guerrero state authorities have charged 29 people in the matter and detained 22 police officers. Three suspects are fugitives, including Iguala's police chief.
Fears have been raised over the fate of the students, after the discovery of a mass grave outside Iguala on the weekend. The grave contained 28 bodies, which were badly burned.
Officials have alleged that local police are in league with a gang called the Guerreros Unidos, with prosecutors saying the drug gang participated in the shootout.
A banner signed "Guerreros Unidos" appeared in the town on Monday, demanding the release of the 22 detained officers. It warned of consequences if the demands were not heeded: "The war has stated."
Mexico's president, Enrique Pena Nieto, has labeled the deaths "outrageous, painful and unacceptable."
The Iguala case threatens to become one of the worst incidents of violence in Mexico in recent years. More than 80,000 people have been killed in gang violence since 2006.
jr/kms (AFP, AP)