Mexico City: Mexican prosecutors on Monday were investigating whether local police officers were involved in the disappearance of 57 students who vanished after deadly incidents in Guerrero state.
Inaky Blanco Cabrera, the state`s chief prosecutor, said the military and state police have been searching for the students -- on the ground and by helicopter -- since the mass disappearance was reported on Sunday.
The students, from a teacher training college, disappeared following a bout of violence in the town of Iguala late Friday and Saturday that left six people dead and 25 wounded in different parts of the southern state.
Four people died in attacks by groups of unidentified gunmen wearing masks who shot at cars and a bus carrying a third-division football team.
Authorities say another two died after municipal police fired at buses that were seized by students protesting against discriminatory hiring practices.
State authorities detained 22 municipal officers.
"It`s undeniable that excessive use of force took place," Cabrera told reporters in Acapulco, adding that there was "no justification for the use of firearms."
He added that authorities are also investigating whether "forced disappearances" took place, a term used for the abduction of people by security forces.