An armed gang robbed `15 lakh from a businessman on a moving bus near the DGP Office at Mylapore on Thursday night, after assaulting him with a knife.
While other passengers managed to nab one of the robbers and noted the registration number of the auto in which the others fled, the police arrested four more gang members within three hours and recovered a part of the loot.
Raja Subbiah, a businessman and a native of Tiruchy, was travelling in the MTC bus (21G) when the robbers, also travelling in the vehicle, picked up a quarrel with him to divert the attention of the passengers and rob him.
The police later recovered Rs 3.5 lakh from the auto after spotting it at Thirumangalam. Syed Ilyas, Santhosh, Prakash, Manikandan and Mohammed Ali have been arrested in connection with the incident.