Three people were killed and atleast 15 were injured when two groups clashed late Tuesday night in Kalyan area of Thane district. Companies of Rapid Action Force have been called in the district to contain violence. Miscreants set afire several houses in Rohidasvada and Doodhnaka. Police sources say that a group of ruffians pelted stones on policemen when they reached the spot of violence. Reports say that several shops were also looted in the area. Bureau Report