One pub closed down and a second was badly damaged in Brighton over the weekend.
The Clyde Arms in Bristol Gardens had to close after 8pm on Sunday after a fight broke out between two rival sets of travellers.
Glasses were thrown as one group burst into the pub and fighting broke out.
The trouble spilled into the street where a woman, armed with a knife, was arrested by police.
The pub stayed closed for the rest of the evening and police maintained a presence in the area.
There were problems during the day where travellers are camped in nearby Wilson Avenue. Firefighters were called twice to extinguish rubbish fires.
Earlier on Sunday, all seven windows of a bar-restaurant were smashed.
A man carrying a 6ft scaffold pole broke a glass picture in the bar as he thrust the pole through windows.
The man fled in a car from Room 101 in Trafalgar Street, but police caught up with him in nearby Pelham Square.
Officers arrested a man and recovered a pole and a hunting knife.
Affy Wajid, 30, and his partner, Neil Masey, 37, said damage ran into thousands of pounds.
They believe the incident may have been a homophobic attack.
Mr Wajid said: "The bar is not exclusively gay, but none of the other Trafalgar Street shops and pubs, which are straight, were attacked."
The partners opened Room 101 in April.
Mr Wajid said: "We were just getting things going here. It has been a hell of a job and now this happens."
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