Lucknow: A police sub-inspector was on Monday killed in an exchange of fire with criminals in Greater Noida in Uttar Pradesh, police said. A police team, led by sub-inspector Akhtar Khan, was sent to the Dadri area on a tip-off that three criminals were present there, Dadri Station House Officer (SHO) Om Singh Yadav told IANS. There was an exchange of gun fire between the three criminals, Tota, Furkaan and Javed, and the police team, in which Khan was killed, Yadav said. The criminals then fled the scene. They are yet to be arrested. Special teams have been formed to nab the three and entry and exit points of the region have been sealed, he said.