However, the third suspect, Najim Laachraoui, is still at large.
The RTBF broadcaster said the pair were known to police. It is believed at least one was among three suspects seen in a CCTV image at Zaventem airport.
Khalid reportedly entered Belgium under a false identity.
Khalid and Brahim El Bakraoui were Brussels residents, RTBF said, citing an unnamed source. Both had a criminal record, but the authorities were not aware of any ties to terrorism.
The third suspect behind the Brussels airport attack is Najim Laachraoui, 25, Belgian newspaper DH said. Laachraoui’ s DNA has been found in buildings that were used by Paris attackers in 2015. He reportedly traveled to Hungary in September 2015 together with the prime suspect behind the Paris attacks, Salah Abdeslam.
Twin explosions at the airport and another at a metro station on Tuesday left about 34 dead and 250 others wounded.