Manchester United's players and staff are reportedly on high alert ahead of this evening's Europa League tie with Anderlecht in Brussels following events that unfolded in Dortmund earlier this week.
An incident involving Borussia Dortmund's team bus on Tuesday, in which three explosions went off in a targeted attack, has seen security increased at a number of sporting events.
The security breach is being treated as a terrorist attack after letters were found close to the scene claiming responsibility for the attack.
According to Manchester Evening News, the Red Devils will be followed by armed police on their way to the ground for the quarter-final first-leg tie with Anderlecht, while a police helicopter will also provide surveillance for the journey to the Constant Vanden Stock Stadium.
Thirty-two people died in the Belgian city a little over a year ago when terrorists targeted the airport and metro system.