Beware of “cops in mufti” — all fake, on the prowl in market clusters across the city, targeting traders.

Police came to know about the fake cops following the arrest of three men in Burrabazar last week.

“The men from Uttar Pradesh pretended to be officers of the Central Bureau of Investigation and robbed a businessman in the wholesale market,” said Ajoy Kumar, the deputy commissioner of police (detective department).

The trio accosted the businessman, who had come to buy clothes, and told him that his movement was suspicious. “Identifying themselves as sleuths from the CBI, they asked the trader to meet a senior officer waiting in a car parked on the other side of the road. On the pretext of searching him, they snatched more than Rs 45,000 from his bag,” said Kumar.

A couple of days later, officers patrolling Burrabazar spotted a trio searching a man’s bag. The cops immediately challenged their identity and arrested them.

With autumn festivities — which bring about a surge in sales — round the corner, the police fear more such gangs will arrive in the city from other states, including Andhra Pradesh, Tamil Nadu and Uttar Pradesh.

“They usually put up in hotels, though a few even rent houses. Their initial targets are cloth retailers, who come to the central business district to replenish their stocks,” said Asish Sengupta, the officer-in-charge of the detective department’s watch section.

“After a few days, they move on to shopping malls and other retail outlets where people throng for their puja buys,” he added.

In shopping malls, a number of women lifters operate posing as customers. “Last year, more than a dozen women from other states were rounded up after they were caught lifting clothes from shop racks,” said Kumar. “Several pickpockets, too, were picked up.”

Listing the steps the police have taken to prevent crimes on Puja-eve, Kumar said: “All specialised wings, like watch and anti-rowdy, have been put on alert. We have deployed a large number of plainclothesmen who will keep a watch on markets from 8am to 11pm.

A crackdown will soon be launched on suspected snatchers and lifters. “Around two dozen criminals have been held in the past month,” said Kumar.