An exploding phone battery caused Eurostar passengers to flee in panic at St Pancras station.
Passengers ran for their lives after hearing a blast and seeing smoke while waiting in the departure area of the station shortly after 8pm on Monday.
Witness Haxie Meyers-Belkin told the Standard: "I was sat near the escalator leading to the platform when I noticed people screaming, dropping their cases.
"It was a mass panic of people running in all directions. People were trying to find corners to hide.
"The smoke was pretty acrid, so I thought something was amiss. But after 25 seconds it became clear it wasn't a bomb attack and it subsided pretty quickly."
The 8.10pm Eurostar service left as scheduled, though fellow witness Katy Lee said that amid the confusion, it departed without "200" disgruntled Parisians.
Posting on Twitter, she also said some people where left shaking and in tears following the scare.
A man, apparently a staff member, was seen photographing the debris of the device on the floor.
British Transport Police and Eurostar have been contacted for comment.
