Rizwan's family has offered a �10,000 reward to catch his killers

Rizwan, 17, was stabbed in West Ham Park, Plaistow, east London, on Sunday when he tried to stop a gang stealing a friend's mobile phone.

Two other 17-year-old boys were arrested on Tuesday over the murder. All three are being held at an east London police station for questioning.

Rizwan is the twentieth teenager to have died as a result of a knife or gun-related crime in London this year.