New Delhi/Patna, Oct. 24 -- Four wanted gangsters from a Bihar-based crime syndicate were killed after more than 40 rounds were exchanged in a fierce shoot-out with a joint team of police from Delhi and Bihar in northwest Delhi's Rohini Sector 32 on Thursday, senior police officers from the two states said. The men, all from Bihar, belonged to a crime syndicate that had dubbed itself "Sigma & Company", responsible for a string of contract killings and extortion operations across north Bihar. The slain gangsters - Ranjan Pathak, 25, the second-in-command of the group; Bimlesh Mahto, 25; Manish Pathak, 33; and Aman Thakur, 21 - were killed after they were intercepted by a joint team of the Delhi Police Crime Branch and Bihar Police's Special ...