Network Rail have confirmed that 1,000m of cable has been stolen from the line between Bedford and Bletchley.
A spokesman told ITV Anglia that rail delays would continue for the rest of the day while engineers worked to make repairs.
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The search is on for a mystery lottery ticket holder in Colchester who has won an £8.1 million prize.
Heavy showers will move north during Saturday and it will feel cool. Sunday will be drier and brighter with long spells of sunshine.
A man who killed two young engineers who were on their way to work in a collision near Littleport has been jailed for five years.