Three men have been charged with terrorism offences in the aftermath of the Brussels attacks, prosecutors said.
They were arrested during raids on 13 addresses on Sunday. A fourth man was released without charge.
Meanwhile, the Belgian Crisis Centre said it had revised the death toll up to 31. So far 28 victims had been identified. Three attackers also died.
The attacks at Brussels airport and on the metro were claimed by so-called Islamic State (IS).
The three men – whose names were given as Yassine A, Mohamed B and Aboubaker O – were charged with participation in a terrorist group, the Belgian prosecutor’s office said.
More arrests have also taken place in relation to what authorities say were planned attacks on France.
A man already in Belgian custody was reported to have been charged in connection with a foiled attack in the Paris region.
Separately, Dutch police announced on Sunday evening that they had detained a Frenchman, 32, in Rotterdam at the request of French authorities.
He was arrested on suspicion of preparing an attack in France and will be extradited to the country. Three other people were also detained.
The Frenchman is allegedly linked to Reda Kriket, who was arrested in a Paris suburb on Thursday and said to be in the “advanced stage” of plotting an attack, AFP news agency reported citing a police source.