A man is fighting for his life after being found unconscious on Bold Street in the early hours.
The 27-year-old, from Northern Ireland, is believed to have been walking down Bold Street towards Hanover Street with three friends when they were assaulted.
Police had initially said the victim was 24, but later clarified his age.
Police and paramedics were called to the scene just after 1am on Saturday to reports that a man was found unconscious on the floor near to Liverpool Central Station.
READ MORE: Forensic officers inspect Bold Street after 'serious' incident
He was rushed to hospital after suffering from serious head injuries during the attack.
His condition is currently described as critical but stable.
The bottom of Bold Street remains cordoned off this afternoon, while police and forensics work at the scene.
Merseyside Police said a full investigation is underway and enquiries are ongoing to trace the offenders involved.
Police are particularly keen to speak to any taxi drivers from the nearby Hackney cab rank on Hanover Street, in case they have vital dashcam footage.
Detective Chief Inspector Paul Parry, said: “The 24-year-old victim was visiting the city with family and we are working to establish exactly what has happened so that we can find those responsible.
"Forensic examinations are currently ongoing at the scene and we will be reviewing CCTV from the area, but I would also like to appeal to anyone who was in the area and has any information, or mobile phone/dashcam footage that may be able to assist our investigation to come forward.
"We appeal to anyone who has information to come forward as soon as possible. If you're a driver who was in the area of Hanover Street at the time of the incident at around 1am- let us know if you have dashcam footage which could help further our investigation."
Drivers can upload dashcam footage to be viewed by police via the following link to the NICE website here.
Anyone who can assist the investigation is asked to DM @MerPolCC or message Merseyside Police Contact Centre on Facebook, quoting reference 0058 of 14 August. You can also pass information anonymously via Crimestoppers on 0800 555 111, or contact them via their online form here.
