The Central Bureau of Investigation on Monday filed cases against people belonging to 20 organisations in Tamil Nadu in connection with anti-Sterlite protests in Thoothukudi in May.

According to the First Information Report, a copy of which is available with, the offences include rioting, disobedience, voluntarily causing hurt, assault to deter a public official from discharging their duty, trespassing, and attempt to murder.

The FIR stated that the sub-collector of Thoothukudi held a meeting on May 20 informing protestors that some groups may indulge in violence and that a permission for a protest on May 22 could not be granted due to “chances of a law and order problem”.

However, a group of protestors decided to go ahead with the protest at the collector’s office on May 22, following which prohibitory orders were imposed from May 21 to May 23. Despite this, protestors belonging to Naam Thamizhar, Makkal Adhikaram, Puratchigara Ilaigner Munnani and other organisations breached security barricades and marched towards the Collector’s office, the FIR said.

The FIR said that some protestors tried to enter the collector’s office by hurling stones and petrol bombs. Police used tear gas to disperse the mob, but the protestors “attacked police with deadly weapons and stones”.

Thirteen people agitating against the expansion of the copper smelter were killed on May 22 and May 23 – prompting the state government to permanently shut down the plant days later. Several people were arrested for rioting, burning vehicles in the premises of the collectorate, pelting stones and damaging public property.

For more than two decades, activists in Thoothukudi have accused Sterlite of contaminating the region’s air and water resources and causing breathing disorders, skin diseases, heart conditions and cancer. From February, there were large-scale protests against the company’s copper smelter, which had the capacity to produce 4.38 lakh tonnes of anodes per annum, or 1,200 tonnes per day.