Manchester United fans face being arrested if they try to get near Anderlecht's ground without a match ticket amid heightened security around Thursday's Europa League quarter-final.
Supporters have also been warned that bags will not be permitted inside the Constant Vanden Stock Stadium as part of strict anti-terrorism measures implemented around Brussels.
The Belgian capital has been on high alert since March 22 last year when co-ordinated attacks in the city killed 32 people and injured hundreds of others.
It means that all public events are subject to enforced security, including army presence, extra security sweeps and controls.