The British Davis Cup team were preparing to set out for Belgium on Monday for a Davis Cup final cast into doubt by the terror attacks that killed 130 people in Paris.
The final is in Ghent, but that city is just 55 kilometres (35 miles) away from Brussels which remained on maximum security alert for a third day amid fears of further violence.
Schools and universities were shut in the capital and the Metro system once again was not operating after Belgium police carried out a series of raids and arrests but failed to find key Paris attacks suspect Salah Abdeslam, who was thought to be hiding somewhere in the city.
The British team, led by world number two Andy Murray, had been due to fly out on Sunday, but delayed their departure by 24 hours to see how the situation evolved.
The tennis final is being played in the 13,000-seat Flanders Expo, which is sold out for all three days starting on Friday.
More than 1,000 British fans were expected to attend to see if they can celebrate a first Davis Cup title win since 1936, with most of them travelling through Brussels by air or rail.
International Tennis Federation (ITF) president David Haggerty said on Saturday he was “greatly concerned” by developments but that preparations for the tie would continue.
Former British number one Tim Henman, though, has cancelled his plans to attend the final.
He was quoted as saying by several national newspapers: “I was going to go, but I am not going any more.
“I was going to take the three girls, I was going to go with my family. With the train and then the going over there, I just thought, ‘Is it really worth the hassle for them?’
“So we are going to be watching at home.”
Henman also had words of support for team leader Murray who lost two ties in straight sets – to Rafael Nadal and Stan Wawrinka – at last week’s ATP World Tour Finals in London.
“I think it was evident in his performance at the O2 that he was a bit distracted, and that’s perfectly acceptable when you’ve got a Davis Cup final around the corner.
“Given the atmosphere and the environment for the match in Belgium, 90 per cent of the support is going to be locals, I think that really will focus his mind. I’m sure he’ll continue as he has done all year and carry the team and do the job out there.”
Murray has been the driving force behind Britain’s run into the country’s first Davis Cup final since 1978, winning all eight of the rubbers he has played – six singles and two doubles – against the United States, France and Australia.
He defeated Belgian number one David Goffin for the loss of just one game in the recent Paris Masters and the team is once again looking to him to win both of his singles and also team up with brother Jamie in the doubles.
“I think they’ll win 3-1 but it won’t be easy. Away on clay is never easy,” Henman said.