A middle-aged man has handed himself into police, claiming to be the man behind a two-year terror campaign directed against children and shop workers.

A poison pen writer, who signed some of his chilling letters Soldier David, is behind a series of threats made in Thornaby, Teesside.

Police made an appeal on Monday for help in catching the person behind a series of up to 20 letters and a similar number of phone calls in which he threatened to murder shop staff and called for a "Dunblane-type massacre". He also referred to children as "the spawn of Satan".

Yesterday, a 45-year-old man claiming to be responsible for the campaign handed himself in to police yesterday.

A Cleveland Police spokeswoman said today: "A 45-year-old man handed himself in to Thornaby Police Station at around 2pm yesterday, claiming to be the letter writer Soldier David."

Officers have searched his home and taken away items for forensic examination and their inquiries were continuing today, the spokeswoman added.