Thirty-four people have been killed in attacks on Brussels airport and a rush-hour metro train in the Belgian capital on Tuesday, triggering security alerts across Europe.
A witness said he heard shouts in Arabic shortly before two blasts struck a packed airport departure area at Brussels airport. The federal prosecutor said one of the blasts was probably triggered by a suicide bomber.
The Belgian health minister said 11 people were killed in the airport bombing and 81 wounded.
The blasts at the airport and metro station occurred four days after the arrest in Brussels of a suspected participant in November militant attacks in Paris that killed 130 people.
Video showed devastation in the hall with ceiling tiles and glass scattered across the floor. Some passengers emerged from the terminal with blood spattered over their clothes.
Smoke rose from the building through shattered windows and passengers fled down a slipway, some still hauling their bags.
Many of the dead and wounded were badly injured in the legs, one airport worker said, suggesting at least one bomb in a bag.
Brussels airport has cancelled all flights until at least 06:00 on Wednesday morning.
All three main long-distance rail stations in Brussels were closed and train services on the cross-channel tunnel from London to Brussels were suspended.