Police say they received a tip-off of a man holding a gun near Pryzm nightclub in Watford town centre last night.

Update: Teenager charged after police seize gun in Watford

An anonymous call was made shortly before 12.30am (Tuesday) and police rushed to the scene and detained four men.

A firearm was seized alongside a vehicle.

Police have launched an investigation into the circumstances surrounding what happened and are appealing for witnesses.

The area is likely to have been quite busy with Pryzm open at the time.

Police are also keen to trace a man who was seen acting suspiciously in Gaumont Approach - a street which runs between Pryzm and Watford Market.

Detective Inspector John Finnegan believes the incident is "isolated" but accepts it may cause some concern within the community.

He added: “Thanks to the person who bravely made the initial report, we were able to immediately locate the suspects and seize a weapon so I would like to thank them for their actions.

“However since then we have made several attempts to contact that person, but the number they provided us is no longer connecting.

“Unfortunately they terminated the call before the member of staff in the force communications room had chance to record any further detail.

“Therefore we are very keen to speak to them, or anyone else who may have seen a man acting suspiciously in the area around Gaumont Approach yesterday evening, as we believe they will have vital information that could assist our enquiries."

Anyone who can help police with their investigation should call police on 101 quoting ISR 12 of August 13 or call Crimestoppers anonymously on 0800555111.

• Three 18-year-old men and a 19-year-old man, all from Watford, were arrested on suspicion of possession of a firearm in connection with this incident. All four are currently in police custody.