Manchester United have been put on high security alert ahead of a match in Brussels tonight in the wake of the bombing attack on Borussia Dortmund's team bus in Germany earlier this week.
The club face Anderlecht in the quarter finals of the Europa League and are taking the threat of another attack 'very seriously', with an 'unprecedented' security operation launched to protect the players.
It comes as security experts say 'no sporting event is safe' from terrorist groups following the bombing, with German authorities arresting a 25-year-old 'Islamist' suspect Iraqi man in connection with the incident.