'Unprecedented' security operation promised for Paris Olympic Games

The organisers of the Paris Olympics have promised an "unprecedented" security operation in the city ahead of the official start of the games later this week, and indeed the signs are everywhere in the heart of the French capital.

Officials have said more than 45,000 police officers are being deployed, while a 6km anti-terrorism barrier has been erected along the banks of the River Seine ahead of the opening ceremony.

Police checkpoints and metal barriers are now a familiar sight in central Paris, while the enormous police deployment means an officer is never more than a few hundred feet away.

Rarely in peacetime has Paris experienced such high levels of security.

Friday's ceremony poses a particular challenge for authorities.

Unlike previous summer olympics, it will not take place inside a stadium; instead, a flotilla of barges will carry thousands of athletes down the River Seine.

To keep participants safe, France will impose a no-fly zone of 150km during the ceremony, while snipers will be deployed on the top of buildings along the route.

Access to the Seine within that 6km route has now been blocked off to anyone without a special pass or QR code to enter.

"For as long as the closing ceremony hasn't finished, we need to remain vigilant," Tony Estanguet, president of the Paris 2024 Organising Committee, said earlier this week.

"Security is our number one priority for Paris 2024," he added.

According to Marc Hecker, a security analyst at the French Institute for International Relations, the main security threats facing Paris ahead of the Olympics come from "jihadis and other terrorist groups from the far right," while nonviolent activists also pose a challenge to the smooth running of the games.

Authorities are particularly