Metropolitan Police said the man jumped into the river but was pulled out swiftly by river police. They said it was not clear if the man was a protester. The BBC, however, reported that he was a cabdriver.
Several dozen cabbies drove slowly and tooted their horns at Tower Bridge on Monday, angry that they are banned from the exclusive traffic lanes designated for Olympic athletes and officials.
The so-called “Games Lanes” around Greater London are set to come into force Wednesday.
• From wire dispatches and staff reports