Ms Nasreen's work still angers Muslims
Police have been put on high alert in India's Karnataka state after violence over an article by Bangladeshi writer Taslima Nasreen left two Muslims dead.
The protesters were killed in clashes with police after the article, which challenges the Muslim practice of veil wearing, appeared in local newspapers.
A curfew has been imposed in the Shimoga area to prevent further unrest.
Ms Nasreen fled her native Bangladesh in 1994 after receiving death threats relating to a book she had written.
Muslims said her work was offensive to them. She left India in 2008 after further protests and went to live in Sweden.
Police say the protesters were killed after police opened fire in Shimoga, 250km (about 150 miles) north-west of state capital, Bangalore, on Monday.
Cases have also been registered against two newspapers for carrying the controversial article, police said.
About 15 people were injured in Monday's violence in Karnataka, and several shops and vehicles set on fire.
As well as the unrest in Shimoga, Karnataka Chief Minister BS Yeddyurappa's home district, there was also violence in the town of Hassan.
Police say Hindu groups joined the unrest in both places after Muslims took to the streets. About 50 arrests have been made in connection with the violence.
"We will not allow communal elements to disturb peace," Mr Yeddyurappa said.