Of the almost 100 people injured, the condition of two was said to be critical in hospital.
The death toll in anti-Sterlite protests went up to 12 after a youth was killed and two others injured in fresh incidents of police firing on Wednesday. Protestors set fire a local administrator's office and burned more than 110 vehicles, according to police, who responded with batons and tear gas before firing on the crowd.
Normal life in the town was virtually crippled on Wednesday, with shops and commercial establishments not opening for business.
District Collector N. Venkatesh said the prohibitory orders were extended in Vembar, Kulathur, Arumugamangalam, Vedanatham, Ottapidaram and Eppodum Vendran in Thoothukudi district.
Elon Musk's LA Tunnel System Costs $1 for a 150MPH Loop Ride
The firm was granted permission in August of that year to dig under up to two miles (3.2 km) public roads around campus. It's no secret that entrepreneurial maverick Elon Musk has big plans for the future of public transportation.
Shops and commercial establishments remained shut, educational institutions were also closed. Public transport from Thoothukudi to other parts of the state has been suspended.
Blaming provocative messages spread through social media, the government in an order said such messages led to a massive gathering of about 20,000 people yesterday in Tuticorin against Sterlite's copper plant which subsequently resulted in violence and police action.
The new spell of violence began this morning, when police used mild force to chase away a large number of anti-Sterlite Movement members and relatives of firing victims from the Government Hospital (GH).
The probe will take into account the "law and order incidents following the siege of the District Collectorate by thousands of persons violating prohibitory orders", an official release said.
"Yes, the situation is tense but it is under control", a senior police officer said.