Brussels attacks: Scores remain critical after bombings
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, BBC News reports.
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, prosecutors said.
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.
Ms de Block said in a statement (in French) that the injured were from 40 nationalities, and 150 were still being treated in hospitals across Belgium.
Many are suffering from burns or wounds normally seen on a battlefield, such as shrapnel injuries. The death toll, the statement said, was still "provisional".
Ms de Block added that four patients were in a coma and had not yet been identified, which was delaying the process of naming victims.
Belgium's king and queen visited the airport on Wednesday and also met some of those injured in the attacks. A minute's silence was held at midday.
Full story