Police in Brussels on Thursday launched a desperate hunt for two men suspected of taking part in the Islamic State bombings that struck at the very heart of Europe.
Under-fire Belgian security officials are tracking one man identified at the scene of a suicide attack on the metro, as well as a suspected bomber seen on CCTV footage at Brussels airport.
European security authorities faced mounting pressure after it emerged that two brothers who blew themselves up at the airport and on a metro train were known to police and that one of them had been deported from Turkey as a "foreign terrorist fighter".
Flags in the shellshocked city of Brussels hung at half-mast as Belgium mourned the 31 people from all over the world killed in Tuesday's attacks, while doctors battled to save scores more injured in the carnage.
Candles, Belgian flags and teddy bears were piling up in the central Place de la Bourse with tributes left to the innocent victims of the attacks.
Outside the bombed metro station of Maalbeek, just a few hundred metres from key EU institutions, a banner read "Why?" in English, French and German.
Hundreds of airport staff and their families carried candles and flowers in a silent march and vigil near the shattered terminal that will stay closed until Saturday.
"We are all one big family. The whole world is with us and we see that we can count on one another but I am very sad, very sad to see such a thing happen," said one staff member who gave his name as Jonathan.
'Common law criminal'
The latest bombings, coming four months after Islamic State jihadists killed 130 people in a series of attacks in Paris, have raised fears of further strikes in Europe, which is battling to deal with home-grown extremists.
The continent is already fighting crises on several fronts, from its worst refugee crisis since World War II to the possibility of Britain leaving the bloc, and leaders have vowed to combat terrorism "with all means necessary".
EU justice and interior ministers will convene later Thursday in Brussels for an emergency meeting to work out a plan to address the threat to Europe posed by jihadists and the application of anti-terrorism laws across the bloc.
On Wednesday, prosecutors said brothers Ibrahim and Khalid El Bakraoui had carried out attacks at Zaventem airport and Maalbeek station, while police sources named bomb-maker Najim Laachraoui as a second airport bomber.
Police have launched a massive manhunt for the third airport suspect, seen wearing a hat and white jacket on CCTV footage from Zaventem departure hall, whose explosive-packed luggage failed to go off with the two other suicide bombers.
It has emerged that the three men identified have links to the Paris attacks in November, underscoring the threat European nations face from the jihadist group.
And fresh questions were raised over European security when President Recep Tayyip Erdogan said Turkey had arrested one of the Brussels attackers last year and deported him to the Netherlands.
A senior Turkish official later confirmed it was Ibrahim El Bakraoui.
"Despite our warnings that this person was a foreign terrorist fighter, the Belgian authorities could not identify a link to terrorism," Erdogan said.
Belgium's Justice Minister Koen Geens denied however that the 29-year-old Belgian citizen had been flagged as a possible terrorist.
'War-like trauma'
"At that time, he was not known here for terrorism," Geens told VRT television. "He was a common law criminal out on parole."
Authorities had already been hunting the Bakraoui brothers, both Belgian nationals with long criminal records, over their links to detained Paris attacks suspect Salah Abdeslam.
Abdeslam's lawyer said his client "didn't know" about the Brussels bombings and has not cooperated with investigators since.
Belgian Foreign Minister Didier Reynders said the attacks, the worst in the country's history, had killed or wounded people of around 40 nationalities, with doctors saying they were treating injuries "seen in war."
Very few of the dead have been formally identified but stories were emerging of lucky escapes and tragic ill fortune of people caught in the wrong place at the wrong time.
Adelma Marina Tapia Ruiz, a 37-year-old Peruvian woman, was killed at the airport but her two young daughters and husband survived because the twin girls had run off and the father was chasing after them.
Doctor Muriel Brugmans, who treated her in hospital, said on Facebook: "Tonight I'm thinking very much about my patient, mother of two adorable little girls.
"She was… so worried for her daughters."
Christian Melot, head of the emergency department at the Erasme hospital in Brussels, said he had treated a young man for heavy bleeding, burns and multiple injuries suffered in the metro blast.
Earlier that day his mother had called him and told him there had been an attack at Zaventem and not to take the metro, but he shrugged off her concerns.
"He said 'Yeah, but it's at Zaventem. It doesn't have with the metro'," Melot said. "He took the metro. He was blown up at Maalbeek station."
The health ministry said Wednesday that the number of people injured had climbed from 270 to 300, 61 of whom were in critical condition.
"It's war," said Jacques Creteur, head of the intensive care unit at Erasme. "It's the kind of trauma seen in war."
"These patients were wounded, shredded… so it's rather a tragic state to see them in," said.
