Updated

Police are investigating a brawl that broke out over the weekend on the sidewalk in Philadelphia's Old City neighborhood, a popular nightspot filled with bars and clubs.

Authorities and witnesses say the fight broke out around 2:15 a.m. Sunday and was caught on video by a person at a bar in the area. Police stationed nearby say they responded after hearing a gunshot and came upon the fight.

At least one woman was being punched and kicked repeatedly. Police say they arrested one man and that a gun fell from his waistband.

It wasn't immediately clear what sparked the fight, which is still under investigation by police.