A 17-year-old boy was attacked and killed in a “sustained and possibly targeted attack” in Canning Town, east London, on Valentine’s Day.

The boy was named locally as Promise Nkenda, and was the third teenager to be stabbed fatally in the capital this year.

Promise is believed to have recently attended the New Directions pupil referral unit in Newham, which is for children excluded or at risk of exclusion from their mainstream school.

Promise was listed as one of the highest achievers at the unit, which is for 14- to 16-year-olds. According to one of the unit’s newsletters, Promise was taken to hospital with a serious illness in 2016, with students running a raffle and other fundraising events to show their support.

One of Promise’s friends, writing on Facebook, said: “Lost my Lil bro Promise Nkenda R.I.P bro forever going to be missed love from myself and the whole ilford family my prayers go out to Mama Annie and the family.”

One witness said the boy had been chased by people in a car before being stabbed. The car then crashed on a nearby street.

The Metropolitan police said officers had been called to reports of a youth with knife wounds in Goldwing Close, Canning Town, shortly after 8pm on Wednesday.

Paramedics from London ambulance service were unable to save the boy and he was pronounced dead at 8.38pm. No one has yet been arrested in connection with the killing, police said.

According to Scotland Yard, he is one of 12 people to be stabbed to death in 2018.

The teenager has yet to be formally identified and officers are informing his next of kin.

Acting DI Perry Benton said: “At this very early stage, we are still piecing together what exactly has happened.

“However, we believe the 17-year-old victim has lost his life following a sustained and possibly targeted attack.

“We would urge anyone who witnessed the incident, or who has any information, to come forward and speak to police as soon as possible.”

Asked if the victim had been run over and stabbed, a Scotland Yard spokeswoman said: “We cannot confirm. Inquiries are ongoing.”

Police have set up a cordon around the scene. Police tape blocked off surrounding roads and uniformed officers were only allowing residents through.