Authorities in Mexico have found four more mass graves in the state of Guerrero. They are believed to contain the bodies of students abducted by police last month following student demonstrations.
Two weeks ago, 43 students disappeared in clashes with the police in the town of Iguala.
They had been holding a protest over hiring practices on 27 September and were last seen being bundled into the back of police vehicles.
Then last week, in the middle of a large search operation, six graves were found containing 28 badly burnt bodies. Experts say it might take weeks to identify them, the BBC reports.
Mexican authorities say the new graves also contain burnt bodies and are in the same area as the first set of graves. Thirty-four people, the majority local police, have been arrested.
Federal Attorney General Jesus Murillo Kara said a formal search had now been launched for the town's mayor, Jose Luis Abarca Velazquez, as well as his wife and head of security. They went on leave after the clashes and have not appeared.