Police are appealing for information after a serious assault in the early hours of Monday morning.
Officers think the assault occurred in St Peter's Square off Seel Street at about 4am.
At about 4.30am a 30-year-old man went to the Royal Liverpool University Hospital with injuries thought to have been caused by a sharp object. The victim is undergoing surgery and is in a critical condition.
It is believed the victim was assault by a group of men.
The area around St Peter's Square and Seel Street has been cordoned off for forensic examination. Officers are checking CCTV from the nearby area and have stepped up patrols in the area.
Detective Inspector Andy Ephgrave, said: "This was an extremely serious assault which has left a man in a critical condition.
"This happened in a busy part of the city centre and I understand people may be concerned but I want to reassure them that incidents such as this are, thankfully, rare and we are doing everything we can to bring the people responsible to justice.
"I would appeal to anyone who was in the area at the time and saw the incident or anything suspicious to call police as you might have really important information for our enquiries."
Anyone with information should call police on 0151 777 4064 or Crimestoppers, anonymously, on 0800 555 111.
More top news
We are into the longest cold spell of winter so far. More wintry flurries and bitterly cold weather to come
Windy today, gusts 40-50mph at the coast. Odd wintry flurry across West Lancs, Cumbria, N Wales, bright and feeling raw elsewhere
Pupils at a school in Skelmerdale have made a heartwarming film about what books they love, and what they want to be when they grow up.