A PRIMARY school caretaker behind a letter bomb campaign which injured eight people was today given an intermediate jail sentence.Miles Cooper, 27, from Cambridge, will serve at least five years after being handed the indeterminate jail sentence.

A PRIMARY school caretaker behind a letter bomb campaign which injured eight people was today given an intermediate jail sentence.

Miles Cooper, 27, from Cambridge, will serve at least five years after being handed the indeterminate jail sentence.

The sentence came after a jury yesterday found Cooper guilty of 11 charges relating to explosive devices he sent to offices in London, Berkshire, Oxfordshire, Kent, Birmingham and Swansea in January and February.

His trial heard that Cooper sent seven letters, five of which exploded, as a protest against Britain's “authoritarian” government.

Eight people were injured when five of the letters exploded.