Police cordoned off the area, but the barriers have since been lifted.
A tourist reportedly spotted the bomb and called the police.
A Metropolitan Police spokesman told Metro, "Police were called at 10:30hrs on Sunday, 25 June, by a member of the public reporting suspected WW1 or WW2 ordnance in the foreshore on the River Thames near to the London Eye."
Growing Underground: London farm housed in WWII air raid shelter
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One Twitter user posted that she had been asked to disembark the London Eye ten minutes after the discovery was found.
"So we barely made it on the #londoneye before everyone was evacuated. News, anyone?"
The official Thames Clipper service twitter account announced that the London Eye Pier had been re-opened after an hour, and apologised for the inconvenience.
It said the boat service would resume as per the timetable.
The area also features the popular London Aquarium and the sites see close to 4 million visitors every year.
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