Central London was on lockdown this evening after a World War Two bomb was found in the Thames causing police to shut Waterloo and Westminster bridge.
It was described as being around 2ft by 1ft in size and after being assessed by Met Police specialists the army bomb disposal unit was called in to deactivate it.
The unexploded device was found in the river close to Victoria Embankment - which was also closed - by civil engineers during excavation works.
The incident is said to have sparked traffic chaos, with motorists being told to avoid the area, after cops cordoned off the area.
Westminster station was shut at the request of the police and passengers were told to leave.
Westminster Police said in a tweet: "Please bear with us as we deal with dredged up suspected WWII ordnance."
Cops were reportedly telling people there was a 'suspicious device' in the water they 'needed to check'.
"Massive crowds" spread around Westminster Bridge after roads were closed, Kris Van de Sander, a freelance journalist from Belgium said.
"Everyone was a little paranoid" he added.
The device was spotted by a dredger watching materials being pulled from the riverbed.
The man told the Plymouth Herald: "We're opposite the Eye and about 100 yards from New Scotland Yard.
"Part of my work is to keep an eye on the items coming out and all day long there's these bucketfuls of muck coming out.
"I suddenly looked down at the barge and shouting "what the f***'s that? That's a f****** bomb!"
Angry commuters took to social media to express their frustration at the 'inconvenience'.
Daniel Robert said: "Well, that's ruined my commute home."
Channon Gray tweeted: "Chaos in Westminster. Roads, bridges and the Underground is shut."
A Metropolitan Police spokesman said that it is not clear how long it will take to secure the area or when traffic is likely to return to normal.
They added: "There are road closures in place in and around the area whilst the item is assessed."
Martin Garside, of the Port of London Authority, said civil engineers had been carrying out civil engineering work at low tide when they discovered the device.
"It looks like a shell but it is definitely a Second World War bomb, it's two feet by one foot diameter," he said. "It was exposed at low tide and we are waiting for the army to deactivate it."
London was heavily bombed by Nazi Germany during the war, and unexploded munitions are still sometimes found.