Twenty-eight people died and 250 were injured in India's northern Haryana state on Friday, as violent protests erupted after a court convicted a self-styled "God man" of raping two women.

Rioting initially erupted in Panchkula, 250km north of New Delhi, minutes after Gurmeet Ram Rahim Singh, 50, was declared guilty of raping two devotees in his ashram in 2002.

Mobs set fire to government buildings and attacked police and TV journalists, smashing the windshields of news vans and breaking broadcast equipment.

Police initially used tear gas and water cannons and then fired bullets in the air in an attempt to control the surging crowd as they vandalised bus stations and government vehicles.