The Paris Olympic Games have officially opened amid heightened security following suspected acts of sabotage targeting the French high-speed train network.

The opening ceremony on Friday was the first for a summer Games to take place outside a stadium. The French capital previously hosted the Olympics in 1900 and 1924.

The athletes paraded on boats traveling along the River Seine for about six kilometers.

US pop superstar Lady Gaga and dancers from the Moulin Rouge cabaret in Paris performed as the boat parade continued.

International Olympic Committee President Thomas Bach delivered a speech at the Trocadero near the Eiffel Tower. He said, "What better place than Paris, to share this magic of the Olympic Games with the whole world."

French President Emmanuel Macron then officially declared the Games open.

The Olympic cauldron was lit by French gold medalists Teddy Riner and Marie-Jose Perec. The balloon-shaped cauldron was then lifted up into the Paris sky.

The ceremony ended without any major confusion after lasting for about four hours.

The Games will run through August 11.