The teenager was attacked on St Margaret's Avenue in the Horsforth area of the city, according to the head of a nearby school.

Police were called to the scene and said another teenage boy had been arrested and a murder investigation has been launched.

Paul Bell, head of Horsforth School, said the victim is a former pupil.

The boy's family has been informed.

Senior investigating officer Detective Chief Inspector Stacey Atkinson said: "Our investigation is at an early stage and we are carrying out extensive enquiries to establish exactly what led to this needless loss of a young man's life.

"We understand the immense impact and huge shock a tragic incident of this nature will will have on the community locally.

"Our neighbourhood police team are working with partners, including schools in the area to offer support and reassurance.

"We have already spoken to a number of witnesses and are keen to hear from anyone who has information about the incident."

Police cordons remain in the area as forensic examinations are conducted.