Four people have died in hospital following last week's triple bombing attack in Brussels, the federal prosecution said Monday, raising the total number of victims to 35.
The attacks took place on the morning of March 22 at the Belgian capital's international airport and at the Maelbeek metro station, near the Brussels seat of the European Union's main institutions.
Thirty-one people died in the explosions, in addition to the three suicide bombers. Four more victims have since died in hospital, a prosecution spokesman said, quoting figures issued by the federal health department.
Twenty-eight victims have so far been identified.
"Four patients deceased in hospital. Medical teams did all possible. Total victims: 35. Courage to all the families," Belgian Health Minister Maggie De Block wrote on Twitter.
Prosecution spokeswoman Ine Van Wymersch said the change in the death toll was due to the fact that the health ministry was responsible for providing the hospital figures, while the prosecution only had direct access to information relating to bodies recuperated from the crime scenes.
The Islamic State extremist group has claimed responsibility for Tuesday's attacks, accusing Belgium of "attacking Islam and its people." Belgium is part of a US-led coalition that has carried out airstrikes against Islamic State in Syria and Iraq.
On Monday, the Belgian police released a surveillance video of a third suspected airport attacker who is believed to be on the run. Previously released pictures showed the man wearing a white jacket and black hat pushing an airport trolley with a black duffel bag.
Belgian media had previously reported that the fugitive suspect was Faycal C, a man taken into custody on Thursday. But Monday's release of the surveillance video indicates that the police are still trying to track down the suspect.
Also Monday, Belgian authorities issued arrest warrants for three people detained in anti-terrorist raids the previous day, charging them with participation in the activities of a terrorist group, the federal prosecution said in a statement.
The three were identified as Yassine A, Mohamed B and Aboubaker O. A fourth person detained Sunday was released without charge.
Belgian police conducted 13 raids on Sunday in connection with a "terrorism file," the prosecution said, without specifying which case.