Chennai: The Madras High Court on Friday asked the Tamil Nadu government to explain the circumstances leading to firing in Thoothukudi.
The court has sought a reply from the state government by June 6.
The high court has also directed Tamil Nadu police not to disturb the families of missing accused in the name of inquiry.
13 people were killed in police firing on May 22-23 when violence broke out at the protest by locals, demanding closure of Sterlite Industries in this district over pollution issues.
Witnesses at the protest said that police in the port city of Thoothukudi in Tamil Nadu gave no warning before firing with live ammunition on protesters seeking the closure of a copper smelter owned by London-listed Vedanta Resources Plc.
The ruling-AIADMK government in Tamil Nadu had on Monday ordered the state Pollution Control Board to seal and 'permanently' close the Vedanta group's copper plant in Tuticorin. Soon after the issuance of the order, top Tuticorin district officials sealed the copper smelter unit premises and pasted the order at the main gate.
State Industries Promotion Corporation of Tamil Nadu (SIPCOT) land, which was allotted by the Tamil Nadu government to Vedanta Sterlite, for phase 2, was also cancelled.
Tamil Nadu Deputy Chief Minister O Panneerselvam had asserted that the government would take resolute steps for the permanent closure of Vedanta group's copper plant.