Police reportedly kettled dozens of protesters close to the Olympic Park on Friday night.
The protesters were from the group Critical Mass, a cycling activist organisation.
Police said they had been given permission to hold a demonstration in south London, on the condition that they did not the River Thames.
The Metropolitan Police Press Bureau said the protesters violated that condition and a number were arrested at Tower Bridge, to the east of central London.
Several hours later, around 40 police vans were seen on Stratford High Street, a short distance away from the Olympic Park stadium.
The incident occurred just as the Olympics Opening Ceremony was getting underway.