Six people have been arrested in connection with the Brussels terror attacks, Belgian prosecutors have said.
At least 32 people were killed and 270 injured when suicide bombs ripped through the airport and a Metro station on Tuesday morning.
Three terrorists died in the explosions and a massive manhunt was launched to track down other suspects believed to be behind the blasts.
Belgian prosecutors said the arrests were made during raids in central Brussels, Jette and the Schaerbeek neighbourhood - where police found a large stash of explosives and other bomb-making material earlier this week in a flat believed used by the suicide bombers.
Schaerbeek residents said they heard blasts during the police raids, but it is unclear of these were explosions or controlled detonations.
The arrests came as officers in France swooped on a man suspected of being in the "advanced stages" of a plot to attack the country, in a raid on the outskirts of Paris.
France's interior minister Bernard Cazeneuve said there were no links "at this stage" between the plot and the terror attacks in Brussels and in Paris in November.
Belgian security services were hunting two men pictured with the suicide bombers shortly before the attacks and believed to be on the run.
One of the men was caught on CCTV carrying a large bag and walking with jihadist Khalid El Bakraoui moments before the bomb detonated, according to state broadcaster RTBF and France's Le Monde newspaper.
Another of the suspected killers, dubbed "the man in white", was pictured pushing a trolley through Zaventem Airport with Najim Laachraoui and Khalid's brother Ibrahim before they blew themselves up.
More details have emerged over exactly what the security services knew about the terrorists involved in the atrocities.
According to reports, the El Bakraoui brothers were plotting an attack on a nuclear power facility and brought forward the Brussels strikes following the arrest of Paris attacker Salah Abdeslam.
The brothers planted a hidden camera in front of the home of the director of research and development at the Belgian nuclear programme, the La Derniere Heure newspaper said.
The footage showed the nuclear boss's comings and goings and prompted investigators to conclude the terrorists "could have put national security in danger like never before", the paper added.
Prosecutors have confirmed the Brussels bombings, for which the Islamic State claimed responsibility, were linked to the Paris attacks in November.
Khalid is believed to have rented a house in Charleroi in Belgium which was used as a hideout for the Paris attackers.
An international warrant was out for his arrest and police had been searching for him since December.
Belgium's interior minister and justice minister offered to resign amid growing questions about why authorities failed to prevent the terror attacks, but the prime minister refused to accept the resignations.
Meanwhile, the family of Briton David Dixon, 53, who is originally from Hartlepool but was living in Brussels and has been missing since the Metro blast, said it was "anxiously waiting" and hoping for "good news" about him.
Home Secretary Theresa May joined counterparts from the European Union for an emergency meeting in Brussels on Thursday to discuss ways to fight terrorism.
Arriving at the meeting, Mrs May said the killings were "cold-blooded and sickening attacks".
She added: "Obviously investigations are still ongoing, but we know that those responsible - Daesh - seek to divide us and harm our way of life and the UK stands ready to support Belgium in any way it can to unite, to defeat these terrorists.
"We will give Belgium the support it needs but our message is clear: The terrorists will not win."
Downing Street said six UK citizens had been injured in the twin attacks, four of whom have been discharged from hospital and two are still receiving treatment.
Flights to Brussels airport have been suspended until Monday, the airport said.