Security will be increased at Champions League games this week after a media outlet supporting the Islamic State group published threats against venues. A pro-IS media channel has published multiple posters calling for attacks at stadiums hosting quarterfinal ties on Tuesday and Wednesday. UEFA said it was aware of the threats but said games in Madrid, Paris and London would go ahead as planned. Ministers in both France and Spain have confirmed enhanced security measures. French Interior Minister Gérald Darmanin said there would be "considerably reinforced" security measures in place when PSG play Barcelona in Paris on Wednesday. Darmanin continued: "I will remind you that only 10 days ago, IS shared a picture of the Munich stadium and said action should be taken against sports venues that host football games — although all sports can be targeted. Given how important the Champions League is for football, we are of course talking to our partners." Two quarterfinals are due to be held in Madrid this week. Real Madrid host Manchester City on Tuesday, while Atletico Madrid take on Borussia Dortmund on Wednesday. Pilar Alegría, Spain's sports minister, has issued a message of "calm" ahead of the games in Madrid and said "more than 2,000 police and civil guard officers" are being deployed. Arsenal play Bayern Munich in London on Tuesday. Metropolitan Police Deputy Assistant Commissioner Ade Adelekan said: "We're aware of online and media reports in relation to calls to target matches across Europe and here in London. "However, I want to reassure the public that we have a robust policing plan in place for tonight's match and we continue to work closely alongside the club's security team to ensure that the match passes peacefully." The pro-IS channel called for violent attacks and featured images of the Emirates Stadium in London, the Bernabeu and Metropolitano Stadiums in Madrid, as well as the Parc des Princes Stadium in Paris. The threatening images shared this week did not refer to any particular match or event and were posted by pro-IS media groups not officially linked to the organization itself. However, it is thought the directive to publish the threats may have come from IS itself, as its leadership recently hinted at close co-ordination between official media operatives and online supporters. Material seeking to incite attacks on channels with long-standing ties to the group have increased in the wake of last month's Moscow concert hall attack, according to specialists at the BBC's Monitoring service. Another image shared last week depicted the Allianz Arena in Munich, which is due to host Bayern Munich's return leg against Arsenal next week. A spokesman for European football's governing body said: "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. "All matches are planned to go ahead as scheduled with appropriate security arrangements in place." Germany is set to host the Euro 2024 European Championships later this year. When asked last month about threats to stadium security, German Interior Minister Nancy Faeser said the "dangers have reached a new level". "The state is arming itself even more strongly against all current threats," she added. — BBC