The Tamil Nadu government on Wednesday formed a commission of inquiry to investigate the deaths of 11 protestors who were killed while they were agitating against Sterlite Copper’s smelter in Thoothukudi on Tuesday, PTI reported. The panel will be headed by retired Judge Aruna Jagadeesan.

The Union Home Ministry sought a report from the state government on Wednesday. The National Human Rights Commission also issued a notice to the Tamil Nadu chief secretary and the state police chief, and asked for a response within two weeks, ANI reported.

Meanwhile, the Madurai bench of the Madras High Court issued an interim stay on the expansion of the Vedanta Group’s Sterlite Copper plant in Thoothukudi. Residents have alleged that the factory is contaminating the region’s air and water resources. They said pollutants from the Sterlite plant have caused breathing disorders, skin diseases, heart conditions and cancer.

Thousands of local residents participated in Tuesday’s protests, which turned violent after the police barricaded the route to the collector’s office. Although the Tamil Nadu government named nine people who were killed, Governor Banwarilal Purohit put the number at 11 on Tuesday evening. Several protestors were injured.

The Madras High Court ordered to preserve the bodies of the deceased until further orders, News18 reported.

Security was tightened and prohibitory orders were issued in Thoothukudi on Wednesday.

Sterlite Copper released a statement expressing “sorrow and regret” at the incidents during the protest on Tuesday. “The company has appealed to the government and authorities to ensure safety of our employees, facilities and surrounding communities,” the statement said. “Sterlite Copper plant is non-operational.”

Actor-turned-politician Kamal Haasan will visit Thoothukudi on Wednesday before heading to Bengaluru for the swearing-in of the new Karnataka government. Dravida Munnetra Kazhagam Working President MK Stalin is also likely to visit the city. He has questioned the role of the state’s chief secretary and asked whether the state government would take action against the police chief.

On Tuesday, Chief Minister Edappadi Palaniswami said the police had to resort to firing to control the situation because the protestors indulged in violence.

For over two decades, activists in Thoothukudi have accused Sterlite of contaminating the region’s air and water resources. Since February, there have been large-scale protests in Thoothukudi where the Sterlite runs the copper smelter with the capacity to produce 4.38 lakh tonnes of copper anodes per annum, or 1,200 tonnes per day.