Paris practises ambitious Olympics opening ceremony

All circulation was stopped on the river through the centre of the City of Light on Monday morning as the vessels sailed the six-kilometre (3.7 mile) route which is set to be taken next July by delegations of competitors, as well as TV crews and emergency services.

For the first time in Olympics history, the opening ceremony is set to take place outside the main athletics stadium, with competitors and officials set to travel through Paris on a flotilla of more than 100 vessels.

Guaranteeing security for participants as well as a crowd of several hundred thousand people on the banks of the Seine is an enormous challenge for organisers.

Around 40 boats simulating the arrival of delegations sailed on Monday, with another 18 vessels being used by emergency services, organisers and the host broadcaster.

"We need to test a new way of filming of the ceremony," event director Thierry Reboul said in advance.

The choreography is being done by French theatre director Thomas Jolly, 41, whose plans remain a secret.

Tickets for around 100,000 prize spots along the river have been sold by organisers, with several hundred thousand people set to be authorised to watch for free from the banks of the river.

The traditional torch relay leading up the games has also been hailed as "unbelievable" by chief organiser Tony Estanguet.

The 80-day relay will see the torch carried from Greece by boat to the southern port of Marseille before featuring at the famed Mont Saint Michel in northern France, the Chateau de Versailles and the French Caribbean.

The Paris Olympics are set to take place from July 26 to August 11.