Thousands of residents in Tamil Nadu’s Thoothukudi protested on Saturday demanding that the Sterlite Copper Smelter Plant, which is reportedly polluting the air and groundwater, be closed.

Most shops and business establishments were closed after members of more than 50 trade associations called for a shutdown. “The 50 associations have extended support to the one-day strike,” M Krishnamoorthy, a coordinator of the protest, told The Times of India.

The residents, especially those living in the Kumarattiyapuram village, have been protesting for weeks against the plant, alleging poor effluent management by the copper producer – part of the Vedanta Group – over two decades.

Local news channels reported that at least 12,000 shops were shut, and autorickshaws and minivans did not ply. The protests came just a month after 250 residents went on a hunger strike after the plant announced expansion plans.

The Vedanta Group on Saturday said the plant has clearances for expansion and that their “primary commitment is to ensure the development and well-being of all the communities around our operations”, PTI reported.

The company aded: “Zero discharge systems, utilisation of waste for sustainable applications, energy efficient systems and stringent emission monitoring are the hallmark of Sterlite and these will only be strengthened through the expansion.”

In 2013, the Supreme Court had fined Sterlite for polluting the land and water in the area after a gas leak. The court had also rebuked the plant for operating without permits for some time.

“There are lot of environmental dangers as well as health dangers, particularly cancer,” Fathima Babu of the Anti Killer Sterlite People’s Movement said, according to The News Minute. “Almost every house is affected by cancer. Children are most affected. Throat cancer has increased. Eye cancer has also gone up. All this is strange and shocking.”