Mexico City, January 8 (RHC-EFE) -- Authorities in Guerrero, the southern Mexican state where 43 students disappeared on Sept. 26, found six clandestine graves containing 10 bodies and 11 human heads, prosecutors said.

The graves were discovered on Tuesday in Tepehuixco, a community outside the city of Chilapa de Alvarez, and most of the bodies had signs of torture, the Guerrero Attorney General's Office said in a statement. Nearly all the victims had been tied up, prosecutors said.

Four black trash bags were found in one of the graves, but officials did not reveal what was in the bags. And prosecutors did not say whether the heads belonged to the bodies found in the clandestine graves or to other victims.

Chilapa de Alvarez is near Chilpancingo, the capital of Guerrero, where 43 Ayotzinapa Rural Normal School students disappeared at the hands of corrupt local officials on the payroll of the Guerreros Unidos drug cartel.

Argentinian and Austrian forensic specialists identified one of the missing students, whose remains were among those found at the municipal dump in Cocula.

More than 70 people, including police and public officials, have been arrested in connection with the events that took place in Iguala on the night of Sept. 26, when municipal police fired gunshots at students from the Ayotzinapa Rural Normal School, a nearby teacher-training facility.