Five people were taken to hospital following a street brawl involving knives and other weapons.
Police are now appealing for witnesses to the incident which happened on Westcliffe Drive in Blackpool.
Officers were called shortly after midnight on Tuesday following reports that a group of people had been seen fighting close to The Layton Institute and Social Club.
There were also reports of weapons being used.
Four men and a woman sustained injuries in the incident, and were taken to hospital.
Some of their injuries were consistent with a blade, and one man, with head injuries, remains in hospital in a stable condition.
A 19-year-old man from Blackpool was arrested on suspicion of assault and possession of an offensive weapon and released under investigation pending further enquiries.
DC Cherie Hall of Blackpool CID said: βIt is believed that this disturbance will have been witnessed by various members of the public and we are appealing for anyone with information or media footage of this incident to come forward and assist officers in establishing the events that unfolded.β
Anyone with information is asked to contact police on 101 or email 8659@lancashire.police.uk quoting log number 0031 of July 6.
Information can also be provided to Crimestoppers anonymously on 0800 555 111.
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