Authorities in Belgium are working to track down further Brussels suspects. There's growing evidence that the "Islamic State" cell behind November's attacks in Paris was also responsible for this week's bloodshed.
European Union interior and justice ministers were to hold emergency talks on Thursday, discussing further responses to Tuesday's bombings of a Brussels airport and metro station, which killed at least 31 people and injured 300. More than 60 victims remained in intensive care.
Investigators were focusing Thursday on finding a man who had been filmed at Brussels airport along with the two suicide bombers who have so far been named, Najim Laachraoui and Ibrahim El Bakraoui.
The unidentified airport suspect was filmed pushing a luggage trolley wearing a cream jacket, glasses and a black hat.
Belgian and French media citing unnamed sources reported Thursday that a fifth attacker might also be at large. A man was filmed carrying a large bag alongside suicide bomber Khalid El Bakraoui - the brother of Ibrahim - in the Brussels metro on Tuesday. It's unclear what happened to him. Belgian prosecutors did not immediately respond to the reports. They have not said overall how many people may have taken part in the bombings.
The terror group "Islamic State" claimed responsibility for both the Brussels attack and the November 13 attacks in Paris which killed 130 people. Some of the Brussels suspects have also been linked to Salah Abdesalam, the main surviving Paris attacks suspect, who had spent four months on the run before he was captured in Brussels last Friday.
Deported from Turkey
Security authorities in Europe are under pressure after Turkish authorities said that Ankara had expelled one of the Brussels suicide bombers back to Europe. According to Ankara, Ibrahim El Bakaraoui was picked up near the Turkey-Syria border in mid-2015.
"Belgium ignored our warning that this person is a foreign fighter," Turkish President Recep Tayyip Erdogan said Wednesday.
It has since emerged that the 29-year-old had been deported to the Netherlands. Officials have said that they cannot detain militant suspects expelled from Turkey without evidence that they have committed a crime.
Ibrahim, 29, had also served jail time in Europe for robbery convictions, but had been released early. His younger brother Khalid had served time for attempted carjacking.
Belgium is holding three days of national mourning following the attacks on its capital.
se/msh (AP, AFP, Reuters, dpa)