Letting loose at local bars can be detrimental to business when aggression, alcohol and after hours activites mingle. Let too loose, and the bar may not be there next weekend.

The owners of Kinvara, Bernie’s Pub, Zodiac Domino Sports Club, Montein Restaurant, The Tap and Tuam-Donagh all faced Commissioner Daniel F. Pokaski at City Hall Tuesday because patrons started fights or loitered outside the bars with open containers of alcohol.

On June 9 at 2:50 a.m., Sergeant Detective James M. Fong, of Boston Police District 14, reported a young woman drinking from a bottle of Magners Irish Cider outside Kinvara without proper identification.

‘Staff must stay there until everyone leaves,’ Pokaski told Kinvara Manager Austin O’Conner yesterday. ‘You do have an obligation.’

But bar staff should not feel obligated to baby-sit their customers, according to Kate Benisek, a College of Arts and Sciences junior.

‘There are some loose cannons and you can’t blame a bar for not controlling them,’ she said. ‘It’s the person’s responsibility to know how the alcohol affects them.’

Loose cannons blew up at The Tap on June 21 at 1:30 a.m., when Detective David W. Dinardi reported two females being punched, kicked and hit with beer bottles by eight other females. The victims claimed bouncers witnessed the assault but did not assist them at all.

‘I was counting money at 3 a.m. when I received a phone call from one of the victims saying she was in the hospital,’ said Robert Yancho, manager of The Tap. ‘I heard a television and laughter in the background, so I immediately wrote up a report.’

Pokaksi looked at his hand-written report, but said Yancho should have called the police instead.

‘If you had called the police, you wouldn’t be here,’ explained Pokaski. ‘If you have a nut cake and in this case, two nut cakes there are going to be problems. Call the police.’

Captain William Evans of Boston Police District 14 said bars are reluctant to call police for fear of losing their liquor licenses.

‘Quite honestly not a whole lot [of bar fights are reported],’ Evans said in an interview last fall. ‘Believe it or not, it’s not in the best interest of bars to call us because if we take a report, they get … a license premise violation.’

If they lose their liquor licenses, the six bars could be out of business. They now await a decision, scheduled for Thursday, from the Boston Licensing Board.