Nottinghamshire Police have been allowed more time to question an 18-year-old man in connection with a knife incident outside Pryzm.
The incident took place at 3:48 am on Monday 6 May and four other men have also been arrested over the events including two aged 24, one aged 19 and one aged 22 but released on bail.
Six men were left with knife injuries needing hospital treatment and one 19-year-old male remains in critical condition.
Notts Police have confirmed that the other five people to be discharged from hospital were the five people arrested.
Detective Inspector Daniel Johnstone said: “The circumstances of the incident are still being investigated but it is believed the altercation started outside as people were leaving the nightclub.
“There were a lot of people in the area at the time and I would appeal for anyone who was there and saw something that could be helpful to the enquiry to come forward.
“If you took mobile phone footage or were driving past and caught some footage on your dash-cam, please let us know. It could be vital evidence.”
The police also said that a cordon which covered a large area at the crime scene has been removed now.
Anyone with information should contact Nottinghamshire Police on 101, quoting incident 119 of 6 May 2019 or Crimestoppers anonymously on 0800 555 111.