Three men were airlifted by helicopter to a Merseyside hospital following an “unprovoked attack” on Formby Beach that featured “an axe and a samurai sword”.

The bank holiday in England was marred by violence at the National Trust site after a “horrific incident” saw a 20-year-old man left in a critical but stable condition.

Two other victims, aged 20 and 16, are both in serious but not life-threatening condition following the spate of stabbings on the beach on Sunday.

A man who witnessed the attack told the local Liverpool Echo: “The lad who was losing the fight pulled out an axe and hit the other lad with it. His mate then pulled out a samurai sword and used that too. It was bad.”

A spokeswoman for the local police force said that they were unable to confirm the weapons used in the attack at this stage of the investigation.

Detective Superintendent Mark Baker said: “We believe that this was an unprovoked attack.

“Last night, officers spoke to a large number of people who were leaving the beach to gather vital intelligence. Every piece of information we are given is vital to our investigation, so I’d like to ask anyone who saw what happened to come forward as soon as possible.

“We understand that this shocking event will cause considerable distress to the community in Sefton, and we are working around the clock to identify who was responsible and bring them to justice.

“After many difficult months, it was good to see people out enjoying themselves at the beach yesterday. The fact that three young people have been attacked in this way is truly shocking and disappointing, and our officers will be increasing patrols in the area over the coming days and weeks.”

On Monday evening, the local police force announced the imposition of a 48-hour dispersal zone in the area, meaning that officers can order people they believe likely to cause crime, nuisance, or anti-social behaviour to vacate the zone.

Under Section 35 of the Anti-Social Behaviour and Policing Act 2014, police officers are also empowered with the ability to seize any item, including vehicles, used in the commission of anti-social behaviour. Those who defy the dispersal order and return to the area will face arrest.

Inspector Graham Fisher said: “We are well aware of the significant impacts of knife-related crime – which have led to three young men needing hospital treatment in the last 24 hours – and the worry this will cause for the vast majority of people in the area who are law-abiding members of the community looking to enjoy the beach and surrounding areas.

“The dispersal zone gives us the powers we need to deal effectively with people and I would urge anyone in the area with any information about anti-social behaviour or violent crime on the beach and dunes to contact us.”

Follow Kurt Zindulka on Twitter here @KurtZindulka