A day after the French Interior Minister outlined the plan in place to secure the opening ceremony and the Paris Games in general, jihadists have circulated images via affiliated media outlets such as the Al-Azaim Foundation and Sarh al-Khilafah, one of which shows a masked man holding a rifle with the caption "Kill them all", listing the stadiums hosting Champions League matches this week.

On Tuesday, Real Madrid take on Manchester City at the Santiago Bernabéu, while Arsenal FC and Bayern Munich meet at the Emirates Stadium. On Wednesday, Atlético Madrid host Borussia Dortmund at the Civitas Metropolitano and FC Barcelona visits Paris Saint-Germain at the Parc des Princes. The end of Ramadan on Tuesday will see the usual escalation in jihadist threats.

The Islamic State threat spans a "hot" spring and summer, highlighting security concerns for two major European sporting events: the UEFA EURO 2024 in Germany from 14 June to 14 July and the Paris Olympic Games from 26 July to 11 August.

Paris has long studied how best to protect the city from terrorist attacks. Macron called for greater confidence to reassure the public about possible terrorist attacks and insisted that France has a 'Plan B' for the opening ceremony.

Not only will French security be at work at the Olympics, but foreign assistance will also be welcomed to counter the terrorist threat. "Several foreign nations will reinforce us in critical areas, such as the handling of dogs, where the needs are considerable," the French ministry said.

President Emmanuel Macron's government raised the alert level to the highest and declared a "terrorist emergency" following the attack on a concert hall in Moscow on 22 March, which killed 144 people and was claimed by Islamic State.

The French Minister for Sport, Amelie Oudea-Castera, told France 2 that there is no terrorist threat to the Olympic and Paralympic Games, but that France will continue to do what's necessary to neutralise the terrorists monitoring them.

The Olympic Games have been targeted in the past, particularly in two powerful countries such as Germany - Munich 1972 - and the United States - Atlanta 1996. The gathering of spectators and athletes, and above all the global attention that an event of this magnitude attracts, makes it attractive to those who see disruption or terrorist attacks.