Burial pits holding the remains of an undetermined number of bodies has been discovered at a hidden gravesite just outside of Iguala, Mexico, where violence erupted last weekend and resulted in the deaths of six individuals and the disappearance of 43 students. On Monday, hitmen linked to police confessed to killing 17 of the 43 missing students. However, family members of the victims don't believe that they may be buried in the grave.

Aytozinapa Normal School, where the missing students attended, is like many schools in Mexico's rural teachers college system, which is known for radical and militant protests that often involve hijacking delivery trucks, buses and other vehicles.

Bloodshed broke out Sept. 27 when city police shot at buses, according to state prosecutors. The buses had been hijacked by students from Aytozinapa. The violent protest concluded with three young people dead and 25 people wounded.

Hours later, unidentified masked men fired shots at two taxis and a bus that carried a soccer team on the main highway, killing two people on the bus and one in a taxi.

Guerrero State Prosecutor Inaky Blanco didn't voice any details regarding the number of bodies or whether there was any indication that the remains belonged to the missing students. And Juan Lopez Villanueva, an official with the Mexican government's National Human Rights Commission, later said that six burial pits were unearthed but didn't comment on the potentiality of the bodies belonging to the missing students.

The grave sat hillside within the rugged territory of Iguala's poor Pueblo Viejo district, and the cordoned-off area was guarded by marines, soldiers and federal state police who kept journalists at bay and away from the site, which held approximately 28 badly burnt bodies.

Authorities discovered the unmarked graves on Oct. 4 after the deadly police shooting on Sept. 27, which was part of a series of clashes and shootings that rocked Iguala throughout Sept. 27 and early into the next day.

Guerrero state authorities originally said 57 students were reported missing, but that number was later reduced to 43. Local police are being investigated for their roles in the disappearance of the students. State investigators have seized footage that showed local police arresting an undetermined number of students following the initial incident. Up to 22 officers now face homicide charges for the disappearance and possible slaughter of the students. The involvement of criminal groups has likely infiltrated the police force and town's government.

Vidulfo Rosales, a human rights lawyer helping the families of the missing students, said prior to the discovery of the burial pit that relatives believed that the youth were turned over to a drug gang by police. Students who escaped the shooting said that other students were carried away by several police pickup trucks, according to Rosales.

"The suspicion, the hypothesis, is that they are being held by organized crime gangs that operated in collusion with the police," Rosales said.

Guerrero, a southern state, is an area that's known for its violence and poverty, which feeds local social unrest, corruption and clashes over drug gangs over territory.