Five men were stabbed at a Great Gatsby-themed New Year's Eve party at a bar in Sheffield.
South Yorkshire Police were called to Crystal Bar on Carver Street at 02:20 GMT following reports people had been "stabbed or slashed".
Two men in their 20s are in a critical condition in hospital while three others, also in their 20s, suffered "superficial injuries", the force said.
A temporary closure notice was posted outside the bar.
It states the bar's closure is necessary "to prevent nuisance or disorder". The matter is due to be discussed at Sheffield Magistrates' Court on Tuesday and the closure could last for up to three months.
Only the bar's owner or the people who live at the premises can enter the property at Kendal Works in the city centre.
Ch Supt Shaun Morley said: "We have reviewed the incident and surrounding circumstances and we believe that to protect the public, the closure order is necessary.
"The use of senseless violence in one of our city centre licensed venues is something that will not be tolerated."
Police are conducting extra patrols in the area while inquiries continue.