Police officers are working overtime as part of the investigation into the death of 17-year-old Tavis Spencer-Aitkens, who investigators believe knew his attackers.

So far, five people – including two teenagers – have been arrested in connection with the incident in Packard Avenue shortly before 4.50pm on Saturday.

A 41-year-old man, from the Ipswich area, arrested on suspicion of conspiracy to murder on Saturday evening, remains in custody after police applied for a warrant of further detention from magistrates on Monday morning.

As a result of further enquiries, officers detained four more people in the Colchester area of Essex on Monday afternoon.

The four males, aged 16, 18, 20 and 22, who all have Ipswich links, were arrested on suspicion of conspiracy to murder and brought to Suffolk for questioning.

The victim, of Pownall Road, died after being taken to Ipswich Hospital for treatment.

A post-mortem concluded that the cause of death was as a result of a single stab wound.

He had been walking from the shops in Queen’s Way when approached and attacked by two males on bicycles. They were then joined by four to five other males who further assaulted him, before all the offenders fled the scene.

Superintendent Kerry Cutler said: “This was a cowardly and violent attack on a 17-year-old boy in daylight hours in the street.

“We believe it was targeted. We believe that Tavis would have known the people responsible.

“I strongly feel that people in the community will know who did this, and urge anybody with any information whatsoever to contact us.”

A police pod will remain in place this week, near the junction of Packard Avenue and King’s Way. Another mobile station will be set up in different locations around Ipswich.

Response officers and the area safer neighbourhood team are currently working 12-hour shifts.

Officers are appealing to anyone with CCTV, dash cam or mobile phone footage in the area of Queen’s Way, Packard Avenue, Rands Way or King’s Way, between 12pm and 7.45pm on Saturday.

Anyone with information is asked to contact the major investigation team by uploading information mipp.police.uk/operation/804, calling 101 and quoting reference 30192/18, or contacting Crimestoppers anonymously on 0800 555 111.