The Swedish FA's head of security has told The Times the police operation for Wednesday's Europa League final in Stockholm will be "one of the biggest" seen in the country.
Manchester United face Ajax at Stockholm's Friends Arena two days after an explosion at an Ariana Grande concert in Manchester that has left 22 people dead. It was the latest in a series of deadly terrorist incidents in Europe in recent times, which include a truck attack that caused five deaths in Stockholm last month.
UEFA has said it has "no specific intelligence" to suggest the final will be a target but The Times has reported that at least 1,000 armed police officers will be present at the stadium in Stockholm.
The Swedish FA's Martin Fredman told the newspaper: "The police operation is huge, it's one of the biggest in Sweden. There will be a lot more cops nearby the stadium and they will have special weapons, automatic weapons.
"Every police officer has a pistol but this time some of them will have automatic weapons."
Manchester United's executive vice-chairman Ed Woodward told MUTV that the club, who cancelled Jose Mourinho's news conference on Tuesday in response to the attack, had been heavily affected.
"Words don't really do justice for how we all feel," he said. "We're numb. The events were sickening and all our thoughts at the moment are with the victims and the families affected by it. It was very sombre flying over with the directors this morning and it was all we were talking about, to be honest.
"We've met with UEFA and sat with them and gone through different things we can do around the game, and they accepted we can wear black armbands and have a minute's silence for the victims."
Asked about its impact on United's preparations, he said: "We've got a job to do [on Wednesday], no question about that, and that hasn't been changed but I think what happened last night really put things into perspective.
"Success on the pitch really is nothing compared to the pain and suffering going on back home, that is really where our thoughts are at this point in time."
Ajax manager Peter Bosz has said the match has lost its "glow" after the attack in Manchester.
"Tomorrow evening should be a football feast, but because of events in Manchester, we're all affected, particularly as we're playing against Manchester," Bosz said. "It's horrible. My heartfelt sympathies."