Packages bound for the US discovered on board two freight planes - one at East Midlands Airport in the UK and a second found in Dubai - were found to contain explosives.
The suspect packages were addressed to synagogues in Chicago.
The Belgian Government has requested greater vigilance for passengers and freight flights originating from Yemen and the US and also for US-bound flights. Increased security measures are now in place for both passenger and freight flights.
Belgian Mobility Minister Etienne Schouppe (Flemish Christian democrat) says that passengers will hardly notice the extra security measures that will mainly focus on luggage.
The Belgian Government's crisis centre at the Interior Ministry is monitoring the situation closely.
Belgium is not increasing its level of preparedness for terrorist atrocities at home or against Belgian interests abroad. Existing security measures around potential American and Israeli targets are being maintained.