Police on Tuesday arrested a man who had allegedly fired a gun during a clash between two groups of construction material suppliers at Bondel Gate around Sunday midnight.

An improvised firearm was seized from Shiva Tiwari, alias Rajkumar, who was arrested from the Maidan area. The cops said the 28-year-old was a resident of Kasba.

Five others had earlier been arrested in connection with the clash.

"We suspect the seized firearm was the one from which all the bullets were fired during the turf war. We will send the firearm and empty cartridge shells recovered from the spot for a ballistic test. The test will confirm whether or not the bullets were fired from the firearm we have seized," an officer of Gariahat police station said.

Though the police have found two empty cartridge shells on the spot, residents claimed to have heard at least half a dozen gunshots.

"We are looking for four more persons who were involved in the attack with bullets and bombs," the officer said.

The midnight clash under the Bondel Road flyover, barely a kilometre from Ballygunge Phari, was another instance of open fight for spoils of the syndicate business, which has become a major law-and-order problem since the change of guard in the state in 2011.

Around 11.55pm on Sunday, Pappu and his men attacked Bobby Singh, who had a narrow escape as a bullet grazed his right hand, and his associates. The attackers hurled bombs, too. Investigations revealed the attack was part of a running turf war between Bobby and Pappu.

"The area along Bondel Gate Road is witnessing a realty boom and Bobby has bagged big contracts for supplying construction materials to realtors," a police officer probing the incident said.

"Pappu, who operates in the Kasba-Tiljala belt, was desperate to get a foothold in the Bondel Gate area. Earlier, the two had threatened each other as Bobby was not ready to share territory with Pappu."

Sources at Gariahat police station said extensive raids were being conducted to arrest all culprits following a nod from senior officers.

Residents have called senior IPS officers narrating how bombs were hurled and bullets fired for over half an hour in the area.

The city witnessed at least three incidents of firing over syndicate business in the past couple of months.

In September, a 10-year-old boy returning home from a shop in Entally suffered a bullet wound in his leg after being caught in a clash.

Two days later, Rajesh Mondal suffered a bullet wound in his right knee while trying to help a man in his Garia neighbourhood whom syndicate rivals were thrashing.