A general view of Arsenal's Emirates Stadium ahead of the Champions League quarterfinal 1st leg soccer match between Arsenal and Bayern Munich in London, Tuesday, April 9, 2024. This week's Champions League soccer games will go ahead as scheduled despite an Islamic State terror threat. (AP Photo/Frank Augstein)
Police arrive to patrol outside Arsenal's Emirates Stadium ahead of the Champions League quarterfinal 1st leg soccer match between Arsenal and Bayern Munich in London, Tuesday, April 9, 2024. This week's Champions League soccer games will go ahead as scheduled despite an Islamic State terror threat. (AP Photo/Frank Augstein)
Police officers patrol outside the Santiago Bernabeu stadium, ahead of the Champions League quarterfinal first leg soccer match between Real Madrid and Manchester City in Madrid, Spain, Tuesday, April 9, 2024. This week's Champions League soccer games will go ahead as scheduled despite an Islamic State terror threat. A media outlet linked to the terror group has issued multiple posts calling for attacks at the stadiums hosting quarterfinal matches in Paris, Madrid and London. (AP Photo/Andrea Comas)
Police officers escort the bus carrying the Real Madrid players outside the Santiago Bernabeu stadium, ahead of the Champions League quarterfinal first leg soccer match between Real Madrid and Manchester City in Madrid, Spain, Tuesday, April 9, 2024. This week's Champions League soccer games will go ahead as scheduled despite an Islamic State terror threat. A media outlet linked to the terror group has issued multiple posts calling for attacks at the stadiums hosting quarterfinal matches in Paris, Madrid and London. (AP Photo/Andrea Comas)
A memorabilia vendor outside Arsenal's Emirates Stadium ahead of the Champions League quarterfinal 1st leg soccer match between Arsenal and Bayern Munich in London, Tuesday, April 9, 2024. This week's Champions League soccer games will go ahead as scheduled despite an Islamic State terror threat. (AP Photo/Frank Augstein)
Police officers arrive at the Santiago Bernabeu stadium, ahead of the Champions League quarterfinal first leg soccer match between Real Madrid and Manchester City in Madrid, Spain, Tuesday, April 9, 2024. This week's Champions League soccer games will go ahead as scheduled despite an Islamic State terror threat. A media outlet linked to the terror group has issued multiple posts calling for attacks at the stadiums hosting quarterfinal matches in Paris, Madrid and London. (AP Photo/Manu Fernandez)
Police officers check and seal the sewage system adjacent to the Santiago Bernabeu stadium, before the Champions League quarterfinal first leg soccer match between Real Madrid and Manchester City in Madrid, Spain, Tuesday, April 9, 2024. This week's Champions League soccer games will go ahead as scheduled despite an Islamic State terror threat. A media outlet linked to the terror group has issued multiple posts calling for attacks at the stadiums hosting quarterfinal matches in Paris, Madrid and London. (AP Photo/Manu Fernandez)
Police officers stand guard outside the Santiago Bernabeu stadium, ahead of the Champions League quarterfinal first leg soccer match between Real Madrid and Manchester City in Madrid, Spain, Tuesday, April 9, 2024. This week's Champions League soccer games will go ahead as scheduled despite an Islamic State terror threat. A media outlet linked to the terror group has issued multiple posts calling for attacks at the stadiums hosting quarterfinal matches in Paris, Madrid and London. (AP Photo/Andrea Comas)
Police officers cordon off the road outside the Santiago Bernabeu stadium, ahead of the Champions League quarterfinal first leg soccer match between Real Madrid and Manchester City in Madrid, Spain, Tuesday, April 9, 2024. This week's Champions League soccer games will go ahead as scheduled despite an Islamic State terror threat. A media outlet linked to the terror group has issued multiple posts calling for attacks at the stadiums hosting quarterfinal matches in Paris, Madrid and London. (AP Photo/Andrea Comas)
Police officers take positions outside the Santiago Bernabeu stadium, ahead of the Champions League quarterfinal first leg soccer match between Real Madrid and Manchester City in Madrid, Spain, Tuesday, April 9, 2024. This week's Champions League soccer games will go ahead as scheduled despite an Islamic State terror threat. A media outlet linked to the terror group has issued multiple posts calling for attacks at the stadiums hosting quarterfinal matches in Paris, Madrid and London. (AP Photo/Andrea Comas)