A group of bike-borne youths turned up outside a Trinamul office in Belgharia on Saturday night and allegedly assaulted a few men seated inside and dragged some of them out before opening fire.

Police said Manas Bardhan, one of the men who were inside the office, suffered a bullet wound. He has been admitted to a private hospital off EM Bypass.

Another man in the office, Sabya Gyne, was injured after being assaulted by the butt of a revolver.

Investigators have spoken to Gyne a number of times to try and understand the sequence of events leading to the 10pm attack at Trinamul office. Six persons have been arrested.

Witnesses said that while fleeing the spot, the attackers had fired a few rounds in the air.

Madan Mitra, former transport minister and local Trinamul MLA, reached the spot with some of his supporters soon after the attack. “There is an attempt to create trouble... by some youths who are being instigated politically,” he said.

A preliminary investigation has revealed that the two groups had clashed over their returns from a syndicate, officers said.