SECURITY forces investigating clashes in southern Mexico found a mass grave on Saturday night, sparking fears the pits might hold the bodies of 43 students missing since last week’s violence.

Guerrero state prosecutor Inaky Blanco did not say how many bodies were in the hillside burial pits and declined to speculate about whether the dead were the missing students.

Governor Angel Aguirre said the victims had been “savagely slaughtered.”

Last weekend’s bloodshed was sparked when city police opened fire on buses hijacked by protesting students from a teachers’ college, killing three and injuring 25.

A few hours later masked gunmen shot at vehicles carrying a football team, killing three more.

Mr Blanco said local police were being investigated for their part in the disappearance. Twenty-two are facing homicide charges, while a further eight people were arrested over the weekend — some with alleged links to organised crime.