Multiple people have been injured and a "major incident" declared after a series of stabbings in the English city of Birmingham.
Police and paramedics were called to reports of a knife attack in the early hours of Sunday (local tinme) with further stabbings then being reported.
One witness told BBC Radio 5 Live that the attack seemed like "one group of boys against another group of boys".
West Midlands Police said there were "a number" of victims but the severity of their injuries was not immediately known.
The force denied reports of gunshots being fired and said "it would not be appropriate to speculate on the causes of the incident".
West Midlands Mayor Andy Street said the series of incidents in the Hurst Street area of the city centre appeared to be related but the motivation for them was not yet understood.
A witness, Cara, told 5 Live she had heard racial slurs during the incident, adding it was a "multicultural night" in the clubs near the Arcadian Centre.
"They were not just having an argument and then fighting, it was straight into fists being thrown. There was not much talking going on," she said.
"Drinks were being dropped, bottles that they had obviously bought in the club, rings were falling off so jewellery was going everywhere, clothes were being torn.
"One of the males actually ended up with his hair being pulled out and left with a bald patch."
The Arcadian venue is a hub of restaurants, bars, cafes, clubs and hotels. Featuring an open air central piazza, it is close to the city's Chinese Quarter and Gay Village areas.
Police said the response would be ongoing "for some time" and urged people to stay away from the area.
"We are aware of a number of injured people but at the moment we are not in a position to say how many or how serious," police said.
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