Belgian police are still on the hunt for a third man filmed with two suicide bombers at Brussels airport, as evidence piled up that the same jihadist network was involved in the deadly Paris attacks last November.
Belgium's interior and justice ministers also offered to resign on Thursday over the failure to track an Islamic State (IS) militant expelled by Turkey last year who blew himself up at Brussels airport on Tuesday.
The double blasts at the airport and another attack at a subway station in the Belgian capital killed at least 31 people and injured 270.
Interior Minister Jan Jambon said Prime Minister Charles Michel had asked him to stay on. "In time of war, you cannot leave the field," Jambon told VTM television. Justice Minister Koen Geens also offered to go but would stay on, a ministry spokesperson said.
Belgian authorities are facing embarrassment after Turkey said on Wednesday that last year Ankara expelled back to Europe Ibrahim el Bakraoui, one of the suicide bombers who carried out the attacks on the airport, and warned Belgium he was a militant.
While other militant suspects have not been held on the grounds of lack of evidence, Bakraoui was on parole and barely half-way through a nine-year sentence for armed robbery.
"You can ask how it came about that someone was let out so early and that we missed the chance to seize him when he was in Turkey. I understand the questions," Jambon said. "In the circumstances, it was right to take political responsibility."
With pressure mounting on Europe to improve cooperation against terrorism, European Union (EU) interior and justice ministers were to hold emergency talks on a joint response to Tuesday's attacks.
French Prime Minister Manuel Valls led calls for a "strong European response", but officials say many states, including France, withhold their most cherished data despite a mantra of willingness to share intelligence.
As the investigation continues for the bombings in Belgium, the chief surviving suspect linking the Paris and Brussels attacks, Frenchman Salah Abdeslam, 26, arrested in the Belgian capital last week, appeared briefly in court on Thursday with two other suspects. He was remanded in custody with delay on his detention trial until April 7.
Abdeslam, a French citizen, was arrested in Brussels on March 18 after a four-month manhunt in the wake of the November 13 shooting and suicide bombing rampage by Islamic State (IS) militants that killed 130 people in Paris. His lawyer, Sven Mary, told reporters in Brussels that he hoped Abdeslam's return to Paris could happen "as soon as possible ... Regarding going to France, I think it's really a question of weeks."
Paris prosecutor Francois Molins had said last week that at worst it could take three months for Abdeslam to be handed over to France after the suspect said he would oppose extradition. Investigations into Tuesday's bombings — also claimed by IS — have pointed in Abdeslam's direction as well, indicating that the same jihadist network was involved in both the Paris and Brussels attacks, police said.
Mary said Abdeslam was due in court in Brussels on March 31 to face a European arrest warrant issued by France. This warrant is a procedure reserved for EU member states that speeds up the traditional extradition process by preventing government authorities from blocking any transfer.
Asked whether Abdeslam, born and raised in Brussels, was still helping police investigators, Mary declined to comment, citing client confidentiality. Mary had said on Monday that Abdeslam was collaborating and communicating, and that he was "worth his weight in gold" for the investigation. As the only suspected participant or planner of the Paris attacks in police custody, Abdeslam would be a possible significant source of information on others involved in support networks, financing, and links with IS in Syria, investigators have said.
According to his attorney, Abdesalam did not know of the plan to attack Brussels. "He was not aware," several Belgian media outlets quoted Mary as saying on Thursday.
World leaders have weighed in on the latest attacks. US Defense Secretary Ash Carter said the bloodshed in the administrative capital of the EU, not far from NATO headquarters, showed Washington's European allies should do more to fight IS alongside American efforts in the Middle East.
"The Brussels event is going to further signify to Europeans that, as we have been accelerating our campaign to defeat ISIL in Syria and Iraq and elsewhere, they need to accelerate their efforts and join us," Carter told CNN, using another acronym for IS.
Meanwhile, Turkey's president criticized Belgium for failing to track Ibrahim El Bakraoui, a convicted armed robber whom it expelled last year and who blew himself up at the airport on Tuesday an hour before his brother Khalid, a fellow convict, killed about 20 people at Maelbeek metro station in the city center.
Security sources told Belgian media the other suicide bomber at the airport was Najim Laachraoui, a veteran Belgian Islamist fighter in Syria suspected of making explosive belts for November's Paris attacks, who also detonated a suitcase bomb at the airport. Officials have not publicly confirmed this and Laachraoui was the subject of inaccurate reporting on Tuesday morning when media outlets said been arrested in a raid.
The third suspect captured on airport security cameras pushing a baggage cart into the departures hall alongside Laachraoui and El Bakraoui is now the target of a police manhunt. He has not been named.
The bespectacled man wearing a cream jacket and a black hat ran out of the terminal, federal prosecutors said, and a third suitcase bomb, the biggest of the three, exploded later as bomb disposal experts were clearing the area.
Public broadcaster RTBF said investigators now believed a second bomber was involved in the metro attack close to European Commission headquarters. The man was spotted on security cameras carrying a heavy bag, but his identity was unknown and it was not clear if he had died or escaped. A computer-generated image showed a young man with hollow cheeks, a goatee beard, and thick black eyebrows.