Howrah: Four scrap iron dealers were arrested in Howrah on Tuesday on charges of extortion, criminal intimidation causing threat to life and criminal conspiracy and under the arms act.

The four have been identified as Mukesh Chowdhury from Bihar's Buxar, Viki Rai from Kharagpur, and Devendar Kumar Rai and Ajit Kumar Ray from Rishra.

"A team from the detective department of the Howrah commissionerate rounded up the four from a car near Bajrangbali market in Belur following a tip-off. Two 7.65 bore pistols and nine rounds of ammunition were seized from them," an officer said.

Sources said the accused had multiple cases of extortion and attempt to murder pending against them in Bengal, Jharkhand, Bihar and Odisha.

Sleuths said Chowdhury and his associates controlled the scrap iron market at Bajrangbali market, which is apparently one of the largest such markets in Asia.

"We had been tipped off that they would come to our area to meet some traders in connection with an upcoming auction of the South Eastern and East Coast Railways," an officer said. "People like Chowdhury have found a way to control the bidding."