Terrorism cast a shadow over football again on Tuesday as world ranking leaders Belgium cancelled a training session for a friendly with Portugal in the wake of the Brussels attacks.
More than 20 people have reportedly died in attacks at the airport and a metro station in Brussels, public transport has been suspended and tunnels in Brussels closed as Belgium raised its terror level to 4, which indicates a "serious and imminent" threat.
"Our thoughts are with the victims. Football is irrelevant today. Training cancelled," the Belgian football federation KBVB said on Twitter.
Goalkeeper Thibaut Courtois tweeted: "My thoughts are with the victims and their family!"
Belgium are due to play Portugal on March 29 in Brussels'Stade Roi Baudoui stadium where Tuesday's training session was also originally planned.
Last November, a Belgian friendly with Spain was called off in the wake of the terror attacks in Paris.
The November 13 attacks in Paris took place at the time France were playing world champions Germany in the Stade de France, with three suicide bombers blowing themselves up outside the arena in St Denis.
France played at Wembley against England just four days later, and now return to the Stade de France for the first time. But coach Didier Deschamps said they must look ahead.
"No one can forget what happened, but there's no need to talk about it. We lived very emotional moments, all together. Now we must move forward. All safety measures will be taken," Deschamps was quoted as saying.
The Stade de France has seen several Rugby Six Nations games since the attacks, and security will be tight next week for the date with the 2018 World Cup hosts Russia, which comes after a Friday match at the Netherlands.
The 80,000-seat arena is also the key venue at Euro 2016, staging among other games the June 10 tournament opener between France and Romania, and the final a month later.
Security was further beefed up in France and Interior Minister Bernard Cazeneuve said the Brssels attacks were a reminder that "a very high level of security" will be needed at Euro 2016.
Germany meanwhile host England on Saturday in Berlin (and Italy on March 29 in Munich) in their first game since the Paris attacks.
Their scheduled November 17 match with the Dutch, who failed to qualify for the Euro tournament, was cancelled shortly before kick-off over a terror threat.
"It wasn't easy what happened in Paris and the weeks after. But that has been dealt with," Germany coach Joachim Loew said in an interview published Tuesday on the national federation website.
Loew said "the fight for places in the squad starts in earnest" as the tune-up games between Wednesday and next week Tuesday and involving all 24 Euro teams are the last before coaches will come up with their provisional squads.
The deadline for the final 23-player squad is June 1.
Loew has kicked out Wolfsburg forward Max Kruse for disciplinary reasons, and Spain's Vicente del Bosque has left out Diego Costa as well for the games against Italy and Romania over his at timkes controversial behaviour at Chelsea.
Others like Spain playmaker Andres Iniesta are injured while Wales have left out Gareth Bale (along with Arsenal's Aaron Ramsey) for their games with Northern Ireland and Ukraine in a joint agreement with his club Real Madrid.
England captain Wayne Rooney remains sidelined for the games with Germany and the Dutch, but Tottenham striker Harry Kane and Leicester forward Jamie Vardy will be hoping to impress manager Roy Hodgson.
Hodgson is using the game to assess his striking options, with Daniel Sturridge and Danny Welbeck also in the squad.
"It'll be a chance for these players to show that they have the qualities and the potential that everybody out there seems to think they have and we, of course, as a coaching staff believe they have," Hodgson said.
Italy coach Antonio Conte relishes the chance to play the European champions Spain and world champions Germany.
"I wanted these two friendlies with two favourites to win Euro 2016 because I want to understand how we react against squads of this level," Conte said.