Police investigating the shooting of a 15-year-old boy on his way to school have recovered a “long-barrelled gun”.

The victim remains in a critical condition at Addenbrooke’s Hospital in Cambridge after he was shot on an upmarket housing estate in Kesgrave, Suffolk, at around 8.40am on Monday.

Suffolk Police said that, just over two hours later, at 10.55am, armed officers arrested a boy five miles away in Ipswich on suspicion of attempted murder.

The suspect, a 15-year-old from the Woodbridge area, remains in custody, with detectives granted an extension to detain him for a further 12 hours for questioning.

Witnesses reported seeing the suspect get into a car after the attack, which then drove away.

Superintendent Kerry Cutler said on Tuesday that police have recovered a “long-barrelled gun”.

The force said the gun was recovered from inside a car matching the description of the one seen leaving the crime scene.

The vehicle was seized at the time of the arrest.

Temporary Detective Superintendent David Henderson, the senior investigating officer, said: “This has been a fast-moving investigation, with officers working around the clock since (Monday) morning.

“I appreciate that many people will still be very concerned at an attack of this nature happening in a small town such as Kesgrave, but we continue to stress that incidents like this are extremely rare and that there is no wider threat to the local community.

“In addition, following the initial inquiries that have been carried out, we can confirm that the victim and the suspect are known to each other and at this time there is absolutely nothing to suggest this incident is linked to organised criminality.

“Our thoughts remain with the victim and his family and we continue to offer them our full support.

“Additional patrols to provide reassurance are continuing in Kesgrave and a police pod has been put in place, so local residents have somewhere they can go to speak to officers should they wish to.

“I would urge anyone who has information about this terrible attack to make contact with us as soon as possible.”

Kesgrave High School said that one of its Year 11 students had been involved in a serious incident on the way to school on Monday, but that pupils at the site were safe.

Police are treating the shooting as an isolated incident, and there is thought to be no wider threat to the school or local community.

Anyone with information about the incident is asked to contact the Major Investigation Team quoting reference: 52067/20.