1 of 3
Felix Marquez, Associated Press
Students and relatives of missing students occupy a toll booth as they block a main highway in the city of Chilpancingo, Mexico, Sunday Oct. 5, 2014. Students and relatives are demanding answers a day after security forces investigating the role of municipal police in clashes in this southern city a week ago found a mass grave, raising fears the pits might hold the bodies of 43 students missing since last week in the violence that also resulted in six shooting deaths.

IGUALA, Mexico — The chief prosecutor of Mexico's Guerrero state says authorities have found 28 bodies in a clandestine grave discovered on the outskirts of a city where police engaged in a deadly clash with student protesters a week ago.

State Prosecutor Inaky Blanco says the remains are too damaged for immediate identification and he can't say if any of the dead could be some of the 43 college students reported missing after the confrontation with police.

Blanco says one person detained in the case has told investigators that 17 students were taken to the grave site and killed there. But he stresses that investigators haven't confirmed the person's story.