The incident took place at about 12.40am on Tuesday October 25 at the Rainbow and Dove Public House in Charles Street.
Initial reports suggest that a fire ignited in the beer garden at the pub resulting in two men receiving burn injuries.
The injured men, aged 21 and 20, were transferred to the Nottingham City Hospital where they remain in a stable condition.
A 24-year-old man was arrested in connection with the incident but he has now been eliminated from enquiries but remains in custody for unrelated offences.
Detective Inspector Simon Preston is overseeing the investigation, he said: “We have been actively investigating the incident and studying CCTV footage from the area in a bid to identify the person responsible.
“We would urge the public to take a good look at the images and contact us if they recognise the man or have any suspicions about his identity.
“At this stage there is no evidence to suggest that this incident was homophobically motivated or that the victims were specifically targeted but we are looking into the circumstances surrounding the incident and the events leading up to it.
“We would like to reiterate that incidents of this nature are extremely rare and we would like to reassure people that we will leave no stone unturned in finding the person responsible.
“If you were in the Charles Street area during the early hours of yesterday morning (Tuesday October 25) and you witnessed the incident or the events leading up to it we would urge you to contact the police, if you haven’t done so already.
“It’s vitally important that we speak to everyone who was in the area as the smallest of detail could help us identify the man responsible. Any calls received will be treated in confidence.”
Anyone with any information is asked to contact DS 1152 John Farndon on Leicester (0116) 222 2222, quoting incident number 07:251011 or Crimestoppers, which is free* and anonymous, on 0800 555 111.
* Please note, some mobile ‘phone service providers may charge for this call.