Surface-to-air missiles and SAS style units focused on killing terrorists were today being put in place for a £350million security operation for the start of the Paris Olympics.

Groups such as Al-Qaeda In the Arabian Peninsula – which brought death and destruction to the streets of France in 2015 – have warned they will target prestigious events in France this year, including the Olympics.

The largest peacetime deployment of forces in France’s history was finalised yesterday before tonight’s opening ceremony on the River Seine. One of the military planners, General Lionel Catar, said: “We’re focused and we’re ready.”

He added that around 75,000 soldiers, police and private security agents would be on duty. All are ready to protect competitors as they progress down the River Seine in 80 barges on Friday evening, in front of some 350,000 spectators. These include VIP guests such as Celine Dion and Lady Gaga who will both sing.

The elite National Gendarmerie Intervention Group is on standby, providing everything from rooftop snipers to helicopter-borne rapid intervention teams. A no-fly-zone has been declared across greater Paris for any other aircraft, and mobile weapons systems in place include 12 Crotale New Generation short-range air defence missile units.

Developed in France, the system is specifically designed to protect sites from airborne threats. The missiles have a range of around seven miles and travel at three and a half times the speed of sound.

Commanders at Avord, France’s second biggest airforce base, south of Paris, will coordinate the “air protection bubble”. It will also include four warning aircraft focused on air policing. They will be up for at least 12 hours on Friday to detect threats.

Early yesterday divers could be seen sweeping the Seine for explosives, while drones and a surveillance helicopter whirred above. Sniffer dogs also searched the quays of the Seine and streets. Gerald Darmanin, France’s Interior Ministry, said “the terrorist threat remains high” and “a high level of vigilance” is essential.

Around 250 British officers, and 50 police dogs, will be in France during the Olympics, with some joining French foot patrols in Paris. UK police superintendant Matt Lawler said: “We’re envisaging nearly half a million UK citizens coming to enjoy the Games.”