Police on guard outside the Olympic Stadium acted quickly to stop a cycle group holding an unauthorised protest just as the opening ceremony was getting underway.
Several dozen police vans raced to the outskirts of the Olympic Park on one of the main thoroughfares to the venue where members of protest group Critcal Mass were riding in formation.
Police said the protesters had permission to hold a demonstration in south London, but on condition they do not cross north of the River Thames. A spokesman for Scotland Yard said officers intervened when participants breached regulations restricting their route. Officers blocked off their route and some were forcibly removed from their bikes as others tried to break through a cordon.
The spokesman for Scotland Yard said: “A number of people in breach of regulations imposed on a monthly cycling event have been arrested.”
He said police would confirm the exact number detained later.
The arrested cyclists have been detained under Section 12 of the Public Order Act.