Scores of people remain in intensive care following Tuesday's suicide bomb attacks in Brussels that left 31 people dead, Belgium's health minister says.
Maggie de Block said that of about 300 wounded people, 61 were still in a critical condition, and suggested that the death toll could rise further.
Earlier, prosecutors confirmed they had identified two of the four attackers as brothers Khalid and Brahim el-Bakraoui.
Two other attackers have yet to be named. One died, another is on the run.
Brahim el-Bakraoui blew himself up in the attack at Zaventem airport that killed 11 people while Khalid struck at Maelbeek metro, where 20 people died, and Belgium media reports.
Unconfirmed reports say another of the attackers was the wanted jihadist Najim Laachraoui, who is thought to have links with last year's attacks in Paris.
So-called Islamic State (IS) has said it was behind the attacks.
EU interior and justice ministers are due to hold a crisis meeting in Brussels on Thursday to discuss their response to the bombings.