A shadowy and smoky room; girls singing chartbusters and gyrating to the tunes; guests, mostly drunk, scattering notes, often of Rs 100 and Rs 500.

The scene is common in most bars in the city and its adjoining areas, that have been drawing criminals in increasing numbers since the owners started hiring crooners around two years ago.

And as an obvious fallout, the bars often witness late-night brawls, which at times end in shooting and even loss of lives.

Senior officers of Calcutta police fear that what happened at Howrah’s Hotel Sish Mahal on Monday night is just waiting to happen in any bar in the city. A tiff between two alleged gangsters over tipping the dancers of the Howrah bar had led to one shooting dead the other.

“The bars that hire dancers are violating the law. The crooner’s licence allows only singing,” said an officer.

“The environment in the bars has changed drastically over the past couple of years,” said Gyanwant Singh, deputy commissioner (detective department). “Earlier, people used to enjoy a quiet drink with family and friends. Now, they love the wild ambience of high-pitched songs and dance.”

Several recent incidents suggest that violence can break out any moment. A couple of weeks ago, 10 youths were rounded up after a fisticuff in a Park Street bar. A pistol was seized from one of them.

In a Chittaranjan Avenue bar, two youths recently fired at an employee after being refused a drink. Two regular patrons of a Baguiati bar order their drinks after keeping their firearms on the table, in full public view.

A sleuth, who had kept a watch on several bars in the guise of a customer, said: “People who have managed to make quick money frequent the bars with bundles of notes. They develop contacts with the singers and dancers by giving them generous tips. But there is trouble when others try to befriend the women in the same manner.”

According to the police, around 185 bars in the city have been issued a crooning licence. In the adjoining districts, the figure stands at 150.

“The tendency is to hire crooners and dancers after Mumbai police imposed a ban on them in August 2005. Many of those thrown out of a job following the ban moved to Calcutta, significantly lowering the asking rate,” said deputy commissioner Singh.

The detective department, he said, is drawing up a list of bars that have recruited dancers. “Strict action will be taken against them.”

Praveen Kumar, superintendent of North 24-Parganas police, said: “I have a formed a special team that will conduct surprise checks in the bars.”