Officers bring body bags to the mass grave uncovered in Iguala last night. (AFP)
Officers bring body bags to the mass grave uncovered in Iguala last night. (AFP)

A mass grave has been found outside the Mexican town of Iguala, where recently violence erupted and 43 students went missing.

Guerrero state prosecutor Inaky Blanco said the site was located on the outskirts of the town, which is about 120 miles south of Mexico City. He did not confirm how many bodies were found, or confirm if there was any evidence indicating that they were the students, reports AP.

Last weekend, violence erupted in Iguala when city police shot at a bus that they claim had been hijacked by protesting students from a local teacher's college, killing two students and one person in a taxi.

Afterwards, state authorities said that 43 students had gone missing.

The grave is located on a hillside in Iguala's poor Pueblo Viejo district.

Juan Lopez Villanueva of the Mexican government's Human Rights Commission said that a total of six burial pits were found.

The students were on their way back after collecting money for forthcoming protests against what they argue to be the discriminatory hiring of urban students over rural students on Friday, 26 September.

Police said they commandeered three buses to get back to their college.

Officers pursued the convoy, and when the buses stopped, some students fled, and others were arrested.

When students returned to the bus after three hours, they were fired at by unidentified gunmen. Two students were killed, and another left in a vegetative state. A woman travelling in a taxi was also killed.

Initially, 57 students were reported missing, but the number was reduced when some came out of hiding.

Local police are being investigated for their role in the disappearance of the students. Blanco said that state prosecutors had obtained recordings of officers arresting students en masse after the bus hijacking, and 22 officers face homicide charges.

Experts believe that criminal gangs may have a role in the violence, and could be in control of municipal police.