Operations were almost back to normal at Brussles International Airport two days after power outage at air traffic control Belgocontrol.

Around 200 flights in Belgium have been delayed or cancelled due to power outage at air traffic control Belgocontrol.

Brussels International Airport alone saw cancellation of 147 planes, affecting 20,000 passengers, as the operations were stalled for over six hours on Wednesday.

Power failure at the Brussels ATC resulted in the blanking of radars and screens, forcing the authorities to abort functions at the airport. The emergency generators too were affected in the outage, leaving the ATC with no option.

"We’re not operational, navigation screens are not working in the tower."

Belgocontrol agency spokesman Dominique Dehaene told AFP: "We’re not operational, navigation screens are not working in the tower."

Chaos prevailed at the airports with passengers forming long queues to reschedule their journeys.

The snag came on a day when train drivers in the city began a nation-wide strike disrupting one-third of the services.

Brussels airport stated on its website that the ATC provider is ‘doing everything in its power’ to get the situation back to normal as soon as possible.

"However, delays remain to be expected in the next few days.

We advise our passengers to continue to check their flight information online and to contact their airline for more information."

The flights scheduled to arrive in Brussels were diverted to regional airports, with several of them to Lille airport in France.

The airports of Antwerp and Liege near Germany, and Ryanair hub Charleroi near France also reported delays, cancellations and diversions.

France, Germany, and Luxembourg have, however, said that their airports were not affected.

The flights flying over the country’s airspace at an altitude higher than 24,500ft were not affected as they are controlled by European traffic authority Eurocontrol.

First flight from the EU headquarters, to the US, took off 90 minutes after the ATC resumed functioning.

Image: Around 147 flights were cancelled at the Brussels international airport. Photo: courtesy of Savh.