Belgian police have arrested six people in Brussels as a major investigation continues into attacks that claimed 31 lives in the city on Tuesday.
The arrests were made in the Schaerbeek district. There is no word yet on the identities of the suspects or their possible connection to the attacks.
Separately, in France, a suspect who was plotting an attack has been arrested near Paris, foreign media reported.
The Brussels bombings have been linked to last November's Paris attacks.
So-called Islamic State (IS) has claimed the attacks in both Paris and Brussels.
The arrests in Schaerbeek were made late on Thursday, and followed house-to-house searches in the area.
Also on Thursday evening, French police launched an anti-terror operation in Argenteuil, north-west of Paris, following the arrest hours earlier of a man suspected of planning an attack.
Last November, 130 people died after militants opened fire and detonated bombs in a number of locations in the French capital.
Earlier on Thursday, Belgium admitted that it had made "errors" relating to one of the Brussels attackers.
Turkey has said it arrested and deported Brahim el-Bakraoui last June, warning Belgium he was a "foreign fighter" - but was "ignored". The Dutch authorities had also been alerted, Turkish media reported.