Engineering work on the line during the night overran, delaying some commuter services from Norwich.

Peter Meades, Public Affairs Manager of the train operator One, said a problem developed during work on overhead power lines in the Diss area.

Trains between 0500 and 0600 BST out of Norwich were delayed by about an hour as engineers repaired power lines.

However, he said services from Norwich later returned to normal, although some services out of London's Liverpool Street, which had arrived late, would be delayed by up to 40 minutes for their return journey.

The trains call at stops in Norwich, Suffolk, Cambridgeshire, and Essex.

"Trains from Norwich have returned to normal" Mr Meades said.