Belgian airports were at a standstill Wednesday after an electrical failure at air traffic control in Brussels caused Belgium-bound flights to be diverted, with departures delayed and flights cancelled.

Chaos at Brussels international airport was palpable with 147 flights cancelled by Wednesday afternoon, affecting 20,000 passengers, including a Spanish minister and the negotiators in Greece's bailout talks, reports said.

The electrical failure took place at about 0730 GMT, with authorities hoping for a solution to the problem by 1500 GMT at the latest as electric crews worked to fix the breakdown.

"We're not operational, navigation screens are not working in the tower," Dominique Dehaene, spokesman for Belgium's official Belgocontrol agency told AFP.

All morning, planes headed to the EU capital were diverted to regional airports, in an effort to clear Belgium's airspace, airport authorities said.

Planes overflying Belgium however were not affected, they said.

Traffic was suspended at the regional airport of Charleroi, a low-cost airline hub near the French border, as well as Antwerp and Liege, near Germany.

Several of the flights were being diverted to Lille airport in northern France, a spokesman there said. About 1,000 passengers were to travel on from Lille to their intended destination by bus.

About 600 flights a day arrive or depart from Brussels airport, which serves the headquarters of both the EU and NATO.

"Due to air traffic, Brussels Group meeting will be delayed today," said in a tweet Eleni Varvitsiotis, the EU correspondent for Greek newspaper Kathimerini, referring to the negotiations for Greece's bailout.

"Greek team arrives via Duesseldorf," she said.