Three teenagers, including two 14-year-olds, have been arrested on suspicion of murder after a 17-year-old boy was stabbed to death in a “targeted attack” in Cambridge.

Police were called by paramedics to the scene near Logan’s Meadow, a small reserve next to the River Cam, at 2.52pm on Saturday.

The victim was pronounced dead at 2.56pm.

A 14-year-old boy was arrested at his home in Cambridge at about 11.30pm while another 14-year-old boy and a 17-year-old boy were arrested at their homes in South Cambridgeshire at around midnight, Cambridgeshire Constabulary said.

All were arrested on suspicion of murder and remain in custody.

Detective Superintendent Carl Foster, from the Bedfordshire, Cambridgeshire and Hertfordshire major crime unit, said: “We believe there were members of the public at the scene who spoke with paramedics but left before our officers arrived. I am directly appealing for these people to make contact with us please.

“I would appeal to anyone with information to get in touch with us as a matter of urgency.”

He earlier said police believed the attack was targeted.

Anyone with any information has been urged to contact police on 101.