City of London Police descended on Liverpool Street Station over reports of a suspicious package in the area.
The scenes in London’s financial district come just days after a bucket bomb was set off on a London Underground train at Parsons Green Station, west London, injuring 30 commuters.
Emerging videos have shown dog units being brought in to assess the area.
Surrounding buildings were reportedly told to keep staff inside.
One man reported on Twitter: “Thanks we are all fine - just being asked to not leave building, road in front of us closed leading to Liverpool Street. More armed police.”
Liverpool Street Station has a western entrance on Moorfields at Moorgate station, where the incident unfolded.
Police lifted the cordons after investigating the area.