BRUSSELS -- As the number of victims in the Brussels suicide attacks rose to 35, Belgian police released a video of a mysterious man in a dark hat seen in the company of the bombers who attacked Brussels Airport, indicating that he is still at large.

"Police are seeking to identify this man," the Belgian Federal Police's website said Monday.

The video's release came as a Belgian magistrate also ruled that a man identified as Faycal C., who was arrested during the police raids that followed the March 22 attacks, could be released.

Faycal C. was among those taken into custody and facing preliminary terror charges. Belgian media reported the man was the mysterious suspect in the white jacket and dark hat spotted with the two bombers at the airport the morning of the attacks.

But the Belgian magistrate ruled that new evidence uncovered by investigators revealed there were no grounds to keep Faycal C. in custody and he was released, the Belgian Federal Prosecutor's Office said.

The Belgian Federal Police's website posted a 32-second video of the still-unidentified suspect as he wheels baggage through the terminal alongside the bombers.

"If you recognize this individual or you have information concerning this attack, please contact investigators," police asked.

Tensions remain high in the city, particularly in the Brussels suburb of Molenbeek, where several of those involved in both the attacks on Brussels and those in Paris last November, hailed from.

Jamal Ikazban, a member of the Molenbeek council, tweeted Monday that young people in the neighbourhood were being sent text messages by recruiters. Ikazban did not provide further details, beyond writing that "We must ensure these recruiters can do no more damage."

Belgian authorities also announced that three more people swept up in police raids that followed the attacks on the airport and on a Brussels subway train were being held on charges of participating in terrorist activities.

It was not clear if the suspects ordered held by an investigating judge were linked to the attacks themselves. The three -- identified by Belgian prosecutors as Yassine A., Mohamed B. and Aboubaker O. -- were detained during 13 police searches Sunday in Brussels and the northern cities of Mechelen and Duffel.

The federal prosecutors' office provided no details of the alleged actions committed by the suspects and released a fourth person without charge.

The bombings, the bloodiest in recent Belgian history, were claimed by the Islamic State extremist group and confirmed Belgium's status as an unwitting rear base from which Muslim extremists can stage attacks in Europe. Many of those responsible for the Nov. 13 attacks in Paris that killed 130 people and wounded hundreds came from Belgium.

Four more people wounded in the Brussels attacks died in the hospital, Belgian Health Minister Maggie De Block announced on her Twitter account Monday.

She posted: "Four patients deceased in hospital. Medical teams did all possible. Total victims: 35. Courage to all the families."

De Block had reported over the weekend that 101 of the 270 wounded in the blasts were still being treated in hospitals, including 32 in burn units. A doctor at one of those burn units who had once served in Afghanistan described patients' wounds as shocking.

One week after the devastating attacks, which severely damaged Brussels Airport's departure area, the facility is planning to test its capacity to partially resume passenger service.

Florence Muls, an airport communications manager, said 800 staff members on Tuesday will test temporary infrastructure and new arrangements designed to handle passenger check-ins.

It's too early to say when airport service might actually resume, she said, adding that government and firefighters must approve the new system before Brussels Airport can start handling passenger traffic again.

Before the bombings, Brussels Airport served some 600 flights a day and 23.5 million passengers per year.


Lori Hinnant in Brussels contributed to this report.