Armed police have been called to the scene and London Bridge station evacuated following reports of a 'suspicious item' on a train.
British Transport Police said the station in in Southwark, south London, was closed as a "precaution" while officers analyse the item, reports the Mirror.
A man who was stuck on a train said passengers were told that a "suspect device" had been found, while other witness said it was described as an "unattended package" and people went "running" out of the station as the building was cleared.
Trains are being diverted while emergency services respond to an incident, multiple rail firms have confirmed.
National Rail said there would be no trains at the station until about 3pm.
A passenger told how a "suspicious package" was found on a carriage next to the one where she was sitting.
She tweeted: "Calmly minding my business when police board my train and say there’s a suspicious package in the carriage next to mine and that I have to evacuate the train.
"Then we had to evacuate the platform. Then we had to evacuate the station."
People who were stuck on trains near London Bridge had to disembark on the tracks.
