BRUSSELS (AFP) -- Brussels airport will remain closed Thursday, its chief executive said, after two bomb attacks claimed by the Islamic State group killed at least 15 people there and wrecked the departure hall.

"There will be no passenger flights into and out of Brussels airport tomorrow March 24," Arnaud Feist said in a tweet Wednesday as the probe into the attacks continued.

The departure hall was completely wrecked, with part of the ceiling collapsing down as passengers waiting to check-in struggled out of the smoke-filled building in panic and fear.

Another attack shortly after on the Brussels metro system left about 20 dead, with some 250 injured in both incidents.

In a statement, the airport said it was working with airlines to help thousands of passengers stranded by the attacks, many of them having fled without their baggage as instructed by security staff.

Those who did so could now contact their airline to get their luggage back, it said, but they would still not be able to retrieve their cars.

The resumption of cargo services, either later Wednesday or on Thursday, was being looked at, it added.