13 people were killed after violent clashes broke out in May as the police tried to prevent protesters from marching to the district collectorate at Tuticorin. (Photo: File | AFP)

Chennai: In a major setback for Tamil Nadu government, the Madras High Court on Tuesday ordered CBI inquiry into police firing during the anti-Sterlite protests in Thoothukudi in Tamil Nadu on May 22 in which 13 people were killed.

The court directed the Central Bureau of Investigation to complete its probe within four months.

A division bench of Justice C T Selvam and A M Basheer passed the order on a batch of pleas moved against the police firing and detention of protesters under the National Security Act.

The bench passed the order in the principal seat of the Madras High Court. The court originally reserved its order in the Madurai bench for August 1.

After the high court's order, Tamil Nadu minister D Jayakumar said, "The Court has given its order for the CBI probe. The Tamil Nadu government will definitely meet to decide upon this."

Violent clashes broke out in May as the police tried to prevent protesters from marching to the district collectorate at Tuticorin; the protesters had been demanding a permanent closure of the Sterlite plant at Thoothukudi in Tamil Nadu, owned by London-listed Vedanta Resources, on environmental grounds.