The two suicide bombers who struck at Brussels airport have been named by Belgian state broadcaster RTBF as brothers Khalid and Brahim El Bakraoui.
Citing a police source, RTBF said the brothers were known to the authorities but for involvement in organised crime rather than terrorism.
The development came as t he international manhunt for their accomplice continued with police releasing new pictures of the fugitive which show his face up close.
He was named by local media as Najim Laachraoui, 24, who is also suspected of being responsible for the bombs used in the Paris massacre in November after his DNA was found on suicide belts used in the Bataclan Theatre and the Stade de France.
Belgium has entered its second day of mourning over the terror attacks that shook Europe, killing 34 people and injuring at least 198 - including two Britons.
The first confirmed fatality was mother-of-two Adelma Tapia Ruiz, 37, from Peru.
Others have been reported missing following the double blast in the Belgian capital’s Zaventem Airport, and the subsequent explosion on a tube train at Maelbeek Metro station. Among them was Brussels commuter David Dixon, originally from Hartlepool, who failed to arrive at work on Tuesday morning.
Investigators are focusing on whether CCTV footage captured moments before the airport blasts shows two of the three suspected terrorists wearing single gloves to secrete detonators. Zaventem’s mayor said the explosives were stowed in their luggage and detonated before reaching the security gate.
RTBF reported that Khalid used false documents to rent a property in the Rue De Dries, where an anti-terror raid on March 15 resulted in a man being shot dead.
Algerian Mohamed Belkaid was killed after opening fire on officers as they swooped on the apartment in the Forest area of the Belgian capital, where they discovered ammunition and an Islamic State flag.
The area is south of the Molenbeek district where Salah Abdeslam, who plotted November’s massacre in Paris, was shot and arrested on March 18 after four months on the run.
Belgian authorities said his fingerprints were found in the Forest apartment.
Tuesday’s attacks, condemned as “blind, violent and cowardly” by Belgian Prime Minister Charles Michel, happened four days after the arrest of Abdeslam. Detectives are yet to rule out a direct link between the attacks.
Police are reported to have raided an address given to them by a taxi driver who unwittingly drove the three men to the airport where it is believed officers found another bomb and an IS flag.
A communique which was published in Arabic and French also threatens other countries in the anti-IS coalition with “dark days”, according to the SITE Intelligence Group, which monitors jihadi websites.
It came as transport terminals across the UK and Europe ramped up security measures in the wake of the atrocities.
Images of passengers climbing from a train into a smoke-filled tunnel near Maelbeek station were reminiscent of scenes following the July 7 attacks in London.
Other footage showed the injured from the Metro being treated in the street, while at the airport people could be seen fleeing in terror in video footage shot from an airport car park.
Prime Minister David Cameron is expected to chair a second meeting of the Government’s emergency Cobra committee in response to the attacks, for which IS militants have claimed responsibility.
International leaders united in support for Belgium, with Mr Cameron branding the atrocities “appalling” and US President Barack Obama condemning the “outrageous attacks against innocent people”.
The Prime Minister’s official spokeswoman said Britain was sending a team of specialist police officers to the city to assist with the investigation, while the Foreign Office said it was no longer advising against travelling to Brussels.