As Belgium held another minute of silence for 31 people killed and some 300 injured in Tuesday's terrorist blitz on its capital and intensified a manhunt for two suspects, its authorities came under another kind of attack.
European leaders and terrorism experts lobbed criticisms at the beleaguered country after it emerged that two brothers involved were known to the Belgian authorities, who had ignored warnings about them from other nations, and that one of them had been involved in last year's Paris attacks.
Belgian prosecutors confirmed that they had issued an international arrest warrant in December for Khalid el-Bakraoui, 27, who blew himself up along with many others on a crowded rush-hour train in Brussels.
Prosecutors said yesterday that he had rented the flat used by the cell that carried out the Paris attacks.
On Wednesday, Turkey said it had also warned Belgium about Khalid's brother Ibrahim, 29 - one of the suicide bombers at the Brussels airport - after deporting him twice last year.
Questions had already been raised over how Salah Abdeslam, a prime suspect in the November Paris attacks, could have hidden in a Brussels suburb for months after carrying out the atrocities.
The news of such intelligence failures prompted Belgian Interior Minister Jan Jambon and Justice Minister Koen Geens to offer to resign, but Prime Minister Charles Michel turned them down.
These developments come amid revelations that the police are hunting for one more terrorist who is on the loose - a second bomber at Maelbeek metro station who was seen on surveillance camera to be carrying a large bag.
A manhunt is already under way for a suspect caught on closed-circuit television camera at the airport, whose bomb did not go off.
The third man seen on that security footage with the suspect and Ibrahim el-Bakraoui has now been identified as Najim Laachraoui.
Laachraoui, 25, now said to have killed himself in the airport blasts as well, was a veteran Islamist fighter in Syria and is also suspected of making explosive belts for November's Paris attacks. Before that, he had been a model student in a Brussels Catholic high school, the school's director told Reuters.
"Najim Laachraoui was a very good student," said director Veronica Pellegrini of the Institut de la Sainte Famille d'Helmet, a Catholic school in the ethnically mixed east Brussels borough of Schaerbeek. "He never failed a class."
Prosecutors said Laachraoui's DNA was found in houses used by the Paris attackers last year.
Meanwhile, pressure has mounted on Europe to improve cooperation against terrorism, prompting the European Union (EU) interior and justice ministers to hold emergency talks on a joint response to Tuesday's bombings.
Yesterday, security chiefs from EU states rallied in Brussels for a crisis meeting to discuss what could be done, such as pushing for European Parliament to approve making air-passenger records available.
The EU had apparently told Belgium in February to overhaul its lax border control after immigration officers failed to check suspicious passengers thoroughly.
Also yesterday, Abdeslam, the prime surviving suspect in the Paris attacks who was arrested in Belgium last week after a four-month manhunt, appeared in court amid high military presence. Claiming he knew nothing about the Brussels attack, he asked to be extradited to Paris as soon as possible.
His lawyer Sven Mary told reporters that he hoped Abdeslam's return to Paris could happen in a matter of weeks, noting: "He wants to explain himself in France."