Paris attacks suspect Mohamed Abrini confessed Saturday to being "the man in the hat" caught on video with suicide bombers at Brussels airport last month, images that had sparked a massive manhunt.
Abrini made the admission on the day he was charged with terrorist murders over the November attacks in Paris which left 130 people dead, prosecutors said.
Terror suspect Osama Krayem, a Swedish national, received the same charges over his role in a suicide bombing at a Brussels metro station on March 22, which occurred an hour after the airport blasts. A total of 32 people died in the coordinated attacks.
The latest arrests strengthened the theory that the same cell carried out both France and Belgium's worst ever terror outrages, claimed by the Islamic State group.
The pair were among six arrested in raids across Brussels on Friday. Two were later released but the two others were charged with complicity for allegedly helping Abrini and Krayem.
The judge leading the Belgian investigation into the November 13 Paris attacks charged Abrini "with participation in the activities of a terrorist group and terrorist murders," the federal prosecutor's office said in a statement.
The Belgian of Moroccan origin was the last known Paris suspect still at large. He had been spotted on CCTV cameras at a petrol station north of Paris two days before the attacks there. In the car with him was fellow Paris attacks suspect Salah Abdeslam, who is now awaiting extradition from Belgium to France.
Prosecutors also confirmed Abrini's connection to the Brussels airport attack.
The 31-year-old "confessed his presence at the crime scene" when they confronted him with evidence, including footage of a mystery man in a hat and light-coloured jacket seen next to the two suicide attackers as they walked through the departure hall pushing trolleys loaded with bomb-filled bags.
"He is indeed the third man present at the Brussels national airport attacks," they said in a statement.
"He explained having thrown away his vest (jacket) in a garbage bin and having sold his hat afterward."
The airport images had triggered a furious manhunt for the so-called "man in the hat", who swiftly became one of Europe's most wanted men.
Police stepped up the search on Thursday when they released a video tracing the fugitive's escape route after the blasts and appealed for the public's help in identifying him.
The new footage showed the suspect fleeing the airport and making his way on foot back to central Brussels, appearing calm and composed, before surveillance cameras lose track of him.
The two airport bombers have been identified as Ibrahim El Bakraoui and Najim Laachraoui, believed to be the cell's bomb maker.
Ibrahim's brother Khalid blew himself up at Maalbeek metro station near the European Union's headquarters in Brussels.
Krayem, the son of Syrian exiles, has been identified as the man seen on closed circuit television with Khalid moments before the metro bombing, prosecutors said.
Krayem was also caught on camera buying the bags used to conceal the bombs set off at the airport, they added.
Swedish media said Krayem, 23, who grew up in the southern city of Malmo, and published photographs of him holding a Kalashnikov assault rifle in front of an IS flag said to have been taken in Syria.
In both the Paris and Brussels massacres, several of the suspects came from the largely-immigrant Molenbeek neighbourhood of Brussels, including Abdelhamid Abaaoud, said to have played a key role in Paris, and Abdeslam who was arrested on March 18.
Abdeslam is suspected of playing at least a logistical role in the Paris attacks but unlike his brother Brahim, who blew himself up, he escaped and fled back Brussels, eluding a vast police dragnet for four months.
He has since said that he too had intended to set off a suicide bomb during the Paris attacks but changed his mind at the last minute.
The Belgian authorities have faced intense criticism over the Brussels bombings as it emerged that many of the suspects were known to police for a long time.
Critics say the government has not done enough to prevent radicalisation of Muslim youth in areas such as Molenbeek, with Belgium proportionately the biggest source in the European Union of foreign fighters going to join IS in Syria.
Two charged with complicity
A man arrested Friday and identified as 25-year-old Rwandan national Herve B.M. He is "suspected of having offered assistance" to both Abrini and Krayem, prosecutors said in a statement.
He has been charged with participating in the activities of terrorist group and "complicity in terrorist murders," it said.
It added that 27-year-old Bilal E.M. received the same charge over suspicions he helped Abrini and Krayem.