At least 13 people were killed and more than 65 injured in the protest against the construction of a new copper smelter by the Sterlite industries in Thoothukudi.
The agitation turned violent after protestors were not allowed to march up to the plant, due to which they began to pelt stones and topple police vehicles.
In retaliation, police officials resorted to lathi-charge and tear gas to disperse the crowd.
In the wake of the tragedy, Tamil Nadu Chief Minister Edappadi K Palaniswami announced an ex-gratia of Rs 10 lakh for the kin of the deceased, Rs 3 lakh for those severely injured and Rs 1 lakh for those who sustained minor injuries.
Palaniswami also announced government jobs for the family of the deceased.
Meanwhile, the Home Ministry on Wednesday sought a report from the Tamil Nadu government on the protest. Furthermore, a commission headed by a retired High Court judge, Aruna Jagadeesan, has also been constituted to probe the incident.
The locals are up in arms against the construction of the copper plant, as they claim the plant would pollute groundwater in their area, thus causing serious environmental hazards.
Earlier, Congress President Rahul Gandhi claimed that the protestors were killed for rejecting Rashtriya Swayamsevak Sangh's (RSS) ideologies.
"Tamilians have been massacred because they refused to accept Rashtriya Swayamsevak Sangh (RSS's) ideologies. The RSS and Prime Minister Narendra Modi have been opposed by Tamil Nadu. Also, people of Tamil Nadu cannot be suppressed," he tweeted in Tamil.
The Congress President also extended support to the people of Tamil Nadu.
"Dear Tamil brothers and sisters, we are with you," he said.
Citizens' groups and students' organisations staged a protest outside the Tamil Nadu Bhawan at Chanakyapuri here today, condemning the Tamil Nadu government for the killing of the anti-Sterlite plant agitators in Tuticorin in police firing.
Over 60 protesters raised slogans and demanded parleys with the Principal Resident Commissioner of Tamil Nadu, Jasbir Singh Bajaj.
The security, however, put up barricades and prevented them from entering the campus.
Shutting down the Sterlite plant in Tuticorin, a judicial inquiry into the police firing, action against police officers, an independent inquiry into the company's financing by the comptroller and auditor-general (CAG) were some of the demands of the protesters.
Representatives of the All India Students' Federation, Muslim Yuva Morcha, National Alliance of People's Movements, All India Students' Association, JNU Students' Union and Students Islamic Organisation of India took part in the protest.
The months-long protest in Tuticorin, demanding the closure of Vedanta's Sterlite Copper unit, took a violent turn yesterday with agitators pelting stones and toppling police vehicles after they were prevented from marching towards the plant.
Eleven protesters have been killed in police firing.
