Islamic State 'threatens terrorist attack on tonight's Champions League games' - including Arsenal vs Bayern Munich at the Emirates - with Spanish police also on 'high alert'

The Met is 'aware' of an apparent threat by ISIS against stadiums hosting Champions League games this week - while authorities in Madrid say they are 'on alert'. 

The Al Azaim Foundation, a media channel that is responsible for spreading messages from the terror group, threatened an attack on all four venues hosting this week's quarter-finals. 

That includes the Emirates Stadium in London, which will host Arsenal v Bayern Munich tonight, and the Santiago Bernabeu - where Man City fans will watch their side take on Real Madrid. 

A post shared by the group saying 'kill all' also named the Parc des Princes in Paris and the Metropolitano in Madrid - which are both hosting matches tomorrow. 

The authorities in Madrid have activated all of their 'alert' and 'response systems' following the supposed terrorist threat, according to reports in Spain. 

Former Met Police officer Norman Brennan said the UK security services and police would also respond to the alleged threat depending on how credible they believed it to be. 

Islamic State have threatened to kill fans in London, Paris and Madrid during the next few days

Terrorist group Islamic State have threatened to launch an attack against the four stadiums hosting the first leg of the quarter-finals of the Champions League - including the Emirates

He told MailOnline: 'MI5, MI6 and the Met's anti-terror squad monitor anything and everything to do with terrorism, including attack threats.

'They are very ahead on this kind of thing and will have plans in place depending on how serious they consider the treat to be.

'They'll be a heightened security presence with cameras and cars, while people connected to ISIS monitored.

'Everyone will be on alert while allowing people to get on with their lives - we can't have terrorists deciding how we behave.'

The Spanish Government have activated their security procedures for the Champions League double-header this week. 

It's believed more than 3,000 members of security have been assigned to the fixtures in Spain - Real Madrid vs Manchester City and Atletico vs Borussia Dortmund. 

That reportedly includes over 2,000 agents from the National Police and Civil Guard, who will station themselves in the Spanish capital over the next 24 hours.

Just over 8,000 Manchester City and Borussia Dortmund fans are expected to travel to Spain for the fixtures due to take place on Tuesday and Wednesday evening. 

Head of The Ministry of the Interior, Fernando Grand-Marlaska, said on Tuesday morning: 'In terms of preventing the terrorist threat, the State Security Forces and Bodies have activated all their early warning and protection systems, as well as all their response mechanisms ready and willing.'

He went on to insist that all security protocols have been adopted to ensure the safety of both the players and fans inside the stadiums. 

The Islamic State's last attack took place on March 22 at the Crocus City Hall - which is a large concert hall in Moscow.

Approximately 8,000 Manchester City and Borussia Dortmund fans will travel to Spain for their respective last eight fixtures, due to take place on Tuesday and Wednesday evening

Several men stormed the building, dressed in camouflage and killed 143 people, wounding a further 200.

Manchester City head into their crucial clash with Real Madrid off the back of a 4-2 win against Crystal Palace on Saturday, while Arsenal sit at the top of the Premier League ahead of facing Bayern Munich thanks to their 3-0 triumph over Brighton.