Police in Madrid and Paris have stepped up security before this week’s Champions League quarter-finals after an apparent threat from Islamic State (IS). In London, the Metropolitan police said it had “a robust policing plan” in place for Tuesday’s match between Arsenal and Bayern Munich at the Emirates Stadium. Although Spain’s interior ministry stressed the country’s terror alert remained at level four of five, it said 2,000 officers from the national police and Guardia Civil forces would be deployed to help municipal police patrol Real Madrid v Manchester City on Tuesday and Atlético Madrid v Borussia Dortmund on Wednesday. “This deployment is being coordinated and supported by the state-wide measures established under the anti-terrorist prevention, protection and response plan,” the ministry said in a statement. “The government and the state security forces have taken all relevant initiatives to guarantee the safety of participants and spectators at the two sporting events – as well as the safety of Spanish citizens as whole – so that they can go about their day-to-day business knowing that Spain is one of the safest countries in the world.” France’s interior minister, Gérald Darmanin, said the security around Wednesday’s match in Paris between Paris Saint-Germain and Barcelona was being “considerably reinforced” after a “threat” from IS. “We have seen, among other things, a communication from Islamic State that specifically targets the stadiums,” Darmanin said. He pointed out that IS had called for “an attack on a sporting venue” about 10 days ago. “All sports can be affected,” Darmanin added. “The prefect of police has considerably reinforced security resources [at Parc des Princes]. It goes without saying that, when it comes to important occasions like the football Champions League, we are discussing matters with our partners.” A source close to the matter told Agence France-Presse: “IS has threatened the Champions League quarter-finals, not specifically in France, through one of its communication outlets.” France raised its security to the highest level, urgence attentat (attack emergency) after last month’s Moscow terrorist attack, in which 144 people were killed. IS claimed responsibility for the attack – a claim confirmed by US and French intelligence agencies. British counter-terrorism sources were struggling to recall a previous time when IS had advertised that it intended to carry out attacks on a specific target and then carried it out. What has been seen before is a threat to a high-profile event, such as New Year’s Eve celebrations, which failed to materialise but which, in IS’s eyes, provided a propaganda boost. Sources in the United Kingdom do not believe that there is a specific plot, as evidenced by the fact the UK’s terrorist threat level remained unchanged. It is substantial – the third of five levels – with evidence of a specific plot enough to ratchet it up to maximum. A source said there were no plans to deploy extra Met officers at the Arsenal game beyond the strong plan already in place, which had taken into account mitigating any terrorist threat. The Met deputy assistant commissioner Ade Adelekan, overseeing the policing of London on Tuesday, said: “The UK terrorism threat level remains at ‘substantial’, meaning an attack is likely, and we work closely with colleagues from across counter-terrorism policing in planning for events here in London, to take into account any relevant information that could help us to keep those attending safe. “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. As ever, we ask the public to remain vigilant, and if they see anything that doesn’t look or feel right, then report it to police or security staff.” Sources stress that although there is little belief the threats are credible, the Moscow attacks means they can not afford to be complacent. Arsenal said they were were working closely, as ever, with the Met. “Our planning for tonight’s fixture is no different and our approach, working together with the police and Uefa, is proportionate to the current UK threat level,” the club said. Uefa said it was aware of the alleged terrorist threat and was liaising closely with the authorities at the different venues. “All matches are planned to go ahead as scheduled with appropriate security arrangements in place,” it said.