A teenage Afghan refugee was stabbed to death on a sports field in south-west London in front of schoolchildren playing rugby.

The victim, named by the Evening Standard as 18-year-old Hazrat Wali, was attacked at about 4.45pm on Tuesday on Craneford Way, Twickenham, yards away from Richmond Upon Thames College, which he attended.

Despite the efforts of a teacher who provided CPR after he collapsed, Wali was pronounced dead in hospital shortly after.

A relative from Stanmore told the paper that Wali came to the UK alone two years ago to pursue a better life, leaving his family behind in Afghanistan.

His friend Sahil Kochay said: “He was a very good person. Very caring and loved everyone. He didn’t hold any hate towards anybody. He used to stand up for everyone. I wish I knew why someone would hurt him. He wasn’t the kind of guy to fight.”

Year 8 pupils from nearby Richmond Upon Thames school, aged 12 and 13, who had been playing rugby at the time, were said to be in tears as they looked on.

Their teacher initially attempted to shield them from the incident, before trying to save the 18-year-old.

A witness told the Evening Standard: “There was a teacher in a rugby kit, he was trying to save the boy. He was giving CPR. There were two girls next to him, they were crying. He was a real hero, it was a terrible scene.

“Five minutes before the incident a group of very noisy kids came along heading to the field. The next thing we knew all hell let loose.”

The attack reportedly began on a footbridge, where the victim and suspects had been arguing.

A parent said a group of boys “scarpered” after they were approached by the teacher, before her 13-year-old son saw Wali collapse.

A crime scene is now in place, with two tents erected on the field. There have been no arrests.

Dr Jason Jones, the college principal of Richmond upon Thames College, said: “Our thoughts and prayers are with the student’s family and friends at this difficult time.

“This loss is sure to raise many emotions, concerns, and questions for our students, parents, staff and local community.”

DCI Vicky Tunstall said the incident was “witnessed by a number of people, including groups that were playing football and coaching rugby at the time”.

She called on people who filmed the attack not to share footage on social media.