An official says a protest in southern India by thousands of people demanding that some government jobs be reserved for members of a lower-caste community has turned violent with at least 15 policemen injured.

Chandrababu Nadu, the top elected official of Andhra Pradesh state, said the protesters on Sunday set on fire some train coaches, a police station and dozens of vehicles.

He says the protesters belonging to the lower-caste Kapu community blocked a national highway and disrupted train service by sitting on railroad tracks.

Naidu says passengers on the Ratnachal Express train were unharmed. But he says at least 15 policemen were injured when protesters attacked them with stones near Tuni, a town about 600 kilometers (375 miles) east of Hyderabad, the joint capital of Andhra Pradesh and the newly-formed Telangana states.