Indian police on Tuesday killed nine demonstrators after opening fire on thousands of people demanding the closure of a copper factory due to pollution concerns, a police officer said.

Protesters rampaged for hours in the port city of Tutticorin in the southern state of Tamil Nadu calling for the closure  of the plant run by British-based mining giant Vedanta Resources. 

"Nine protesters were killed in police firing after they attacked the collectors' office," the officer told AFP from the state capital Chennai.