Attacks on the airport and a metro station in Brussels, Belgium on March 22 killed 32 people and wounded more than 300.
Including three dead attackers, the total number of dead stands at 35. The attack was claimed by the Islamic State.
Here's what we know about the men suspected of carrying out the bombings:
Based on fingerprints, police identified Ibrahim el-Bakraoui and his brother Khalid as two suspected suicide bombers the day after the attacks.
Bakraoui, 29, was one of the attackers in the airport. He and his brother were both Brussels-born Belgian citizens.
He was sentenced to nine years in prison in 2010, after shooting at a policeman during an armed robbery, NPR's Dina Temple-Raston reports, citing several U.S. and European counterterrorism officials. He dropped out of the parole system in May and has been on the run ever since.
Turkey's President Recep Tayyip Erdogan says Bakraoui was detained in Turkey in 2015 and deported to the Netherlands — with warnings sent to Belgian authorities alerting them to Bakraoui's ties to terrorism. But Bakroui was released from custody after European authorities couldn't verify those ties, Erdogan's office says.
The Associated Press reported earlier this month that Bakraoui had traveled unimpeded through airports at least twice in the months before the attack. "Suspected by Turkey of being a 'foreign terrorist fighter' and known at home in Belgium as an ex-con wanted for parole violations, Bakraoui was still allowed to board a commercial airliner unaccompanied last summer, flying freely from Istanbul to the Netherlands and disappearing without a trace," the AP writes.
Khalid, 27, bombed the metro station, authorities say.
He was arrested in 2011 for gun possession and carjacking and sentenced to five years in prison, NPR's Dina Temple-Raston reports, citing several U.S. and European counterterrorism officials.
He violated his parole last April when he associated with a criminal colleague, but was released from court custody. Bakraoui violated his parole again in October, and had been on the run since then.
Under the name of Ibrahim Maaroufi (and using a fake ID) Bakraoui is believed to have rented an apartment in Charleroi, near Brussels, which was used as a safehouse and hideout for the terrorist cell, including some surviving Paris attackers. That apartment was raided Dec. 9, putting Bakraoui on international wanted lists.
Bakraoui rented a second flat, again under assumed name, in the Forest district of Brussels; when that flat was raided on March 15, police found a fingerprint of Paris suspect Salah Abdeslam.
Najim Laachraoui, 24, was identified several days after the attack as one of the suspected suicide bombers in the airport.
He's been called "the bomb-maker": According to counterterrorism officials in the U.S. and Europe, Laachraoui's fingerprints were found on the luggage bombs used in the Brussels attack as well as explosives that were used in Paris, NPR's Dina Temple-Raston reports. His DNA was also found on Paris explosives.
Laachraoui left Brussels for Syria in February 2013, breaking off contact with his family, NPR's Phil Ewing reports. Before he dropped out of college, he was an engineering student.
Under the fake name "Soufiane Kayal," Laachraoui traveled with Paris bombing suspect Salah Abdeslam from Hungary into Austria in September, police say.
Abrini, 31, was arrested by Belgian authorities on April 8. A day later, he admitted that he is the "man in the hat" seen in the Brussels airport surveillance footage with Ibrahim el-Bakaoui and Najim Laachraoui, according to Belgian federal prosecutors.
For the last five months, Abrini has been one of the most wanted men in Europe. As we reported, they linked him to November's attacks in Paris through surveillance video and DNA evidence.
"He was seen driving with Salah Abdeslam, one of the Paris attack suspects, from Brussels to Paris last November just before the attack," NPR's Dina Temple-Raston reports. "He's also thought to have driven Abdeslam home."
Belgian federal prosecutors have charged Abrini with "terrorist murders."
Belgian authorities arrested Osama Krayem, a Swedish national, on April 8.
Dina reports that according to Belgian authorities, Krayem "bought the bags that were used to package the bombs in Brussels and he was also with the suicide bomber at the Brussels metro shortly before a bomb went off there last month."
She adds that Krayem went to Syria and that there are reports he came back through Lesbos, Greece.
He's been charged with participating in terrorist activities and "terrorist murders."