A promising sixth form pupil at Heckmondwike Grammar School died from a single stab wound to the back, police have revealed.

Ahmed Hassan, 17, was attacked near Dewsbury Railway Station shortly after 2pm on Saturday.

Ahmed, who was studying A-level Politics, Mathematics, Law and Economics, was with a friend on a Christmas shopping trip.

The school held special assemblies yesterday for sixth formers and said its thoughts and prayers were with Ahmed's family and friends.

It is planning a memorial service for the youngster, from Batley, later in the week.

Head teacher Mark Tweedle said: "Ahmed joined the sixth form at Heckmondwike Grammar School in September, 2006, and quickly impressed as a thoughtful and articulate young man who was gentle, kind and sensitive."

His ambition was to read law at university and he was popular with both staff and fellow pupils.

Mr Tweedle added: "Ahmed will be greatly missed. As one of his teachers remarked If the world were full of Ahmed Hassans it would be a very much better place'.

"All members of the school community are shocked by this tragic event and saddened by the loss of a young man of great promise."

A book of condolence has been opened at the school.

Shahid Malik, Labour MP for Dewsbury, said Ahmed was a model citizen in the wrong place at the wrong time.

His friend held him until the emergency services arrived but he died soon afterwards in Dewsbury and District Hospital.

Mr Malik said the stabbing had cast a shadow over the area, which was preparing to celebrate Christmas and the Muslim festival of Eid.

He said Ahmed's family were taking strength from their faith, but added: "Eid will never be the same again for this family.

"This is a time when family and community ought to be looking forward to positive things. Right across the community, there is a real sense of grief at such a tragic loss of life."

The investigation is led by West Yorkshire Police Homicide and Major Enquiry Team, supported by British Transport Police. Police are appealing to anyone passing Dewsbury Railway Station at 2pm on Saturday to contact them on (01924) 431139.

l Two Dewsbury men, aged 17 and 18, were charged with Ahmed's murder last night and were due to appear before Batley and Dewsbury Magistrates' Court today.

A 19-year-old man, also from Dewsbury, who was being questioned yesterday in connection with the inquiry, has been released without charge. A 24-year-old man who was arrested had earlier been released.