— The mayor of a town in southern Mexico ordered a police attack that resulted in six deaths and the disappearance of 43 students who remain missing weeks later, the country’s top prosecutor said Wednesday.

Iguala police received an order that they said came from Mayor Jose Luis Abarca to prevent the students from disrupting an event at which his wife was presenting a report, Attorney General Jesus Murillo Karam told reporters.

Murillo Karam said Abarca’s wife has been linked to drug gangs and is now considered a fugitive, along with her husband and the Iguala police chief.

He added that authorities have discovered a total of nine mass graves in the area around Iguala that contain 30 bodies, two more than previously reported.

Initial DNA tests have not linked the cadavers to the missing students.

Demonstrators protesting the disappearances set fire to Iguala’s city hall on Wednesday. The extent of damage wasn’t immediately clear, but televised images showed smoke billowing from the building.