Armed police taped off part of Liverpool Street station this afternoon following reports a passenger was carrying a gun.

Transport police, alongside Met officers and City of London Police, shut off the station and ferried commuters outside while they searched the platforms.

But they could find no one matching the man's description, and the station has now reopened.

It is believed the incident happened on one of the National Rail platforms, even though the Tube entrance was closed off.

"We were called to Liverpool Street station following a report that a man had been seen with a gun in his back pocket," said a British Transport Police spokeswoman.

"Officers carried out a full search of the area but no one matching the description provided was found."

The drama kicked off at about 4pm. Passengers left waiting in the sunshine spoke of seeing sniffer dogs in the station, while others took to Twitter to ask what was happening.

"Something's going down at London Liverpool Street," tweeted Siddo Dwyer.

Fleek King ‏asked: "What's going on at Liverpool Street Tube station? Sniffer dogs and armed police have evacuated everyone from the Underground."

And Nick Boyle added: "Armed police coned off half London Liverpool Street station."

Rebecca Graham told the Standard: "Staff had shut down the main entrance to the Underground. Armed police taped off half the station. Sniffer dogs were present. Most people had to wait outside before they allowed the station to function again."