Trains from Cambridge are delayed after the rail station was evacuated.
Abellio Greater Anglia Services through Great Chesterford, Newport, Elsenham and Stansted to London Liverpool Street and CrossCountry trains between Stansted and Cambridge are affected.
Delays are up to an hour.
A spokesman for British Transport Police said there was a security incident at Cambridge Station but officers were stood down as nothing suspicious was found.
An evacuation of the station was ordered, but passengers have been allowed back into the station.
The spokesman added: “Our officers were called to Cambridge rail station on Tuesday, November 24, to reports of a security alert on board of a train.
“The call came into police at 12.47pm.
“Officers attended the station and carried out a full and thorough search of the station. Nothing suspicious was found the station has since reopened.”
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