Security is being stepped up at Champions League games this week after a "threat" from the Islamic State terror group.
A post on a pro-IS media channel listed major football venues along with the comment "Kill Them All".
In a post issued via its de facto media outlet, the Al-Azaim Foundation, the group listed London’s Emirates Stadium, Paris’s Parc de Prince, and the Santiago Bernabéu and Metropolitano arenas in Madrid as targets. The image bears the words “Kill Them All”, along with a black-clad man holding a firearm.
France's interior minister Gerald Darmanin said the jihadist group had threatened all the quarter-final matches on Tuesday and Wednesday, not just PSG's first leg clash with Barcelona at the Parc des Princes.
Darmanin said there had been "a clear threat publicly expressed by the Islamic State".
"The police, whom I spoke to very early this morning, have considerably reinforced the security measures," the minister told reporters.
A source close to the issue told AFP: "IS has threatened the Champions League quarter-finals, not specifically in France, through one of its communication outlets."
In the matches on Tuesday, Arsenal take on Bayern Munich in London and Real Madrid host reigning European champions Manchester City.
In Wednesday's other game, Atletico Madrid face Borussia Dortmund in the Spanish capital.
European football's governing body UEFA said all the matches would go ahead despite the threat.
"UEFA is aware of alleged terrorist threats made towards this week's UEFA Champions League matches and is closely liaising with the authorities at the respective venues," the statement said.
"All matches are planned to go ahead as scheduled with appropriate security arrangements in place."
PSG coach Luis Enrique said in his pre-match news conference: "Who is not worried or concerned by terrorist threats?
"I hope it is a thing we can control and that they are just threats and that nothing will happen."
While sports games and venues have previously been targeted by ISIS, its supporters and other extremist organisations, the group is not known for telegraphing its attacks in advance, preferring instead to storm large public venues and events by surprise.
ISIS has also previously taken credit for attacks by lone supporters or small groups.
While some of these perpetrators have been in close contact with the group or even participated in its deadliest operations in Iraq and Syria, others are likely to have been radicalised remotely or simply inspired by the group’s propaganda.
The recent attack on the Crocus concert hall near Moscow, which killed 144 people, was claimed by the so-called ISIS-Khorasan, a central Asian chapter of the organisation. It is one of the deadliest attacks in ISIS history.
However, the Russian government has tried to blame it on Ukraine, the US and the UK to distract from claims it was warned of the attack in advance.