A man on the tracks claiming to have a bomb forced the evacuation of London’s Charing Cross railway station.
British Transport Police (BTP) was called to reports of a man on the underground tracks at 06:35 BST. Armed police also attended the scene.
A 38-year-old man was detained under the Mental Health Act and no weapon was found. No injuries have been reported.
There was disruption to the mainline and London Underground services but all are now running normally.
The station, which is one of London’s busiest, had re-opened by 08:00.
BTP said officers were called “after receiving reports of a man on the tracks claiming to have a bomb”.
A spokesperson said: “Officers from the Metropolitan Police and BTP specialist firearms officers also attended.
“A 38-year old man was detained by officers and has been held under Section 136 of the Mental Health Act and taken to a place of safety.”
BBC South East Today reporter Amanda Akass was at the scene.
She said there were “dozens of armed counter terrorism officers” with “shields and machine guns”.
“Commuters arriving at Charing Cross this morning walked out of the station and into the middle of a massive police operation,” she said.
“A cordon was rapidly set up and the station closed but there was no air of panic – most commuters seemed curious rather than unduly concerned.
“A man has now been detained by officers and the situation seems to be calming down, the counter terror officers have been pulled away, although there are still several dozen emergency service vehicles here.”
“This is the first time I’ve seen something of this scale,” another eyewitness told the BBC.