BRUSSELS — Is there another Brussels bombing suspect on the run? That's the latest unanswered question to emerge Thursday, part of a growing list amid a lack of public information into the deadly attacks.
Belgian media reported Thursday that the three men declared suspects due to their appearance in an airport surveillance video had at least one accomplice — who remained at large. NBC News was not immediately able to confirm those reports and the federal prosecutor was unavailable for comment.
Belgian authorities have previously said one thing only to say another later.
Officials have not said how many suspects may be involved — perhaps to avoid raising fears of terrorists in the midst — but also haven't named at least one suspect captured in surveillance footage from Brussels airport before the attack.
They have also been unable to give a complete death toll or release the names of victims. No concrete information has been released on how many nationalities were affected in the multinational capital of Europe.
U.S. officials were still working to fully account for Americans in wake of the attacks. One relative of missing couple Justin and Stephanie Shults tweeted that they had been located — then later clarified that incorrect information had been provided and that they have still not been found.
The uncertainty hasn't stopped Belgians from pressing on.
A memorial to the 30-some victims of the explosions has been growing since Tuesday's attacks at the airport and on the subway. Flags are at half-staff and the nation is in an official state of mourning — but Brussels is bustling.
Not everything was fully back to normal — the airport will remain closed until Friday, which is when Secretary of State John Kerry will visit the Belgian capital to express condolences.
However, the unanswered questions have prompted criticism of Belgian authorities' preparedness.
In the first sign that the authorities acknowledge some failures in the case, the country's interior and justice ministers both offered to resign Thursday. However, Prime Minister Charles Michel asked both to stay on.
Belgium's federal prosecutor has stressed the ongoing nature of the investigation. They have confirmed that the man pictured in the center of an airport surveillance image is Ibrahim El Bakraoui, one of two brothers who blew themselves up on Tuesday. Both had been jailed for violent crimes.
Sources suggested that another of the men pushing a luggage trolley in the photo is Najim Laachraoui, who is suspected of being a bomb-maker linked to the Paris attacks; the prosecutor refused to comment.
Just before the Brussels bombings, Belgian officials asked for helping tracking down Laachraoui over his alleged ties to Paris attacker Salah Abdeslam.
Abdeslam spent four months on-the-run as authorities across Europe tried to root him out, finally cornering him in the Brussels neighborhood of Molenbeek. Authorities say he was working with Laachraoui, who had been under the alias of Soufiane Kayal and was traveling with a fake Belgian identity card.
As further signs emerged of Laachraoui's ties to Abdeslam and the Paris attacks emerged, further questions were raised about how he eluded authorities' grasp.
Adding to that, Turkey said that it had deported Ibrahim El Bakraoui to the Netherlands last year and warned Belgium that he was suspected of being a militant.
While the officials would not comment publicly on Laachraoui's status, U.S. and Belgian intelligence sources told NBC News Wednesday that they were certain he died at the airport during the mayhem Tuesday morning.
Abdeslam is in custody in Belgium and his lawyer said Thursday that he would not fight extradition back to France to stand trial for the Paris attacks.
Belgium's tragedy initially prompted other European countries to step up security — and signs were emerging that it could also have an impact on the migrant crisis engulfing the continent.
Recent weeks already have seen E.U. nations tighten border restrictions to stem an influx of refugees and migrants — cutting off a key route, imposing new visa requirements and building more fences.
In wake of the Brussels attacks, Poland's prime minister said her country would no longer take migrants.