Armed police officers evacuated London’s Old Street tube station and sent 20 police cars to the scene after nervous passengers reported hearing a loud bang.
Social media images showed a huge police presence outside the station and eyewitnesses said they were ordered to leave the area immediately.
Officers with guns were seen on guard outside the station and passengers reported being rushed off the platform, but police did not find anything suspicious and no arrests were made.
Twitter user George Maier said: “Just been evacuated out of Old Street station. Armed police came to the platform and told us all to leave immediately.
“Armed police officers on scene, along with multiple ambulances. No clear indication of what is happening. Evacuation still in place.
“Police vans surrounding Old Street station, including unmarked vans now. Armed officers everywhere.”
The Metropolitan Police said they were called to reports of a man “acting suspiciously” on a train – and some passengers reported hearing a loud bang.
The force said: “Police were called at approximately 9.20pm to reports of a man believed to be acting suspiciously on an underground train.
“Several people subsequently reported hearing a bang. No firearm or any other object was seen.
“Officers, including firearms officers and the British Transport Police, attended the Old Street area and the station was temporarily evacuated. There were no reported injuries.
“At this stage nothing suspicious has been found and the incident has now been stood down. There have been no arrests and enquiries continue.”
And the London Ambulance Service said on Twitter: “We also attended this incident but thankfully no patients to treat.”