At least six people were killed and 20 injured in communal violence and police firing in the Old City forcing the authorities to impose indefinite curfew in eight police station areas early on Sunday.

Police opened fire at Gowlipura, Sultansahai, Moghalpura when teargas shells and lathicharge proved ineffective to control the mob indulging in stabbing,  loot and arson late on Saturday night.

Four persons died due to stabbing while two others succumbed to bullet injuries at Osmania General Hospital where about 20 persons injured in stone pelting and attack were admitted, police said.

Rapid Action Forces have been deployed in the riot-hit areas to maintain peace and order.

Commissioner of city police RP Singh reviewed the situation in wee hours and decided to impose curfew in eight police station areas including Shalibanda, Moghualpura, Bhawani Nagar, Chatrainaka, Meerchowk, Rein Bazar and Dabirpura.