An altercation took place between MNS activists and supporters of Congress candidate Sanjay Nirupam in a north west suburb following which his police bodyguard fired two rounds in the air to disperse the crowd, police said on Thursday.

The incident took place when Nirupam had gone with some supporters to the Lokhandwala complex area of suburban Kandivali last night where about 200 MNS activists stopped him and questioned what he was doing there, they said.