Simon Thompson was caught up in the events around London Bridge and rushed into the basement of a nearby restaurant for safety.
He told Sky News that there were “about 20 of us” adding: “People were looking on their phones, people checked twitter and rang relatives who checked on news websites.”
When he finally left the building he had been in he said all he could see was “lots of first aid kits and medical kinds of things and lots of armed police”.
Simon went on to explain that the area was “very busy” and there was a lot of people so it was hard to tell what was happening.
London Bridge Terror: Simon Thompson ran into the basement of a nearby restaurant
London Bridge Terror: At least two people have been struck by a van
Speaking about the moment he knew it was safe to leave the building, he said: “The police had to tell us, they forced us out.
“They told us it was not safe.”
Witnesses told Express.co.uk that a white van had appeared to purposeful hit pedestrians on London bridge at 10.08pm.
A police officer at the scene urged people to run from the bridge.
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London Bridge Terror: Simon said that police 'forced' him out of the building as it wasn't safe
Two other incidents are ongoing in Borough Market and Stockwell, where police have confirmed shots had been fired.
London Metropolitan Police have urged members of the public to “remain calm, but be alert & vigilant”.
They tweeted: “We are using all necessary skills & resources at #LondonBridge #BoroughMarket #Vauxhall.”