Violent protests have broken out in the southern technology hub of Bangalore over a Supreme Court order to divert water from reservoirs to a neighbouring state.

The protests have forced shops, businesses and schools to close in Bangalore, capital of Karnataka state, which has been ordered to release water into a river to ease a shortage in neighbouring Tamil Nadu.

Vehicles with Tamil Nadu registration plates have been attacked and protesters have blocked roads by burning tyres and effigies of politicians.

Karnataka Home Minister G. Parameshwar said police reinforcements had been deployed, particularly in areas inhabited by ethnic Tamils who could be a target.

"We have intensified security and stepped up vigil in Bangalore to ensure peace and maintain law and order," Parameshwar told reporters.

"I appeal to the people, especially the protesters, not to attack anyone or damage public property, including buses, cars and transport vehicles."

The move followed a state-wide strike on Friday that forced hundreds of offices to close in Bangalore, home to many of India's top technology companies.

India suffers severe water shortages that cause frequent tensions between states.

Earlier this year the government was forced to deploy troops to secure a canal supplying water to New Delhi after it was sabotaged by protesters in neighbouring Haryana state, causing days of shortages in the capital.