Schools and many metro stations in Brussels have reopened after being shut four days ago in a security crackdown following the Paris attacks.
But the Belgian capital remains on the highest alert, with hundreds of armed police and soldiers on patrol.
Authorities fear the possibility of Paris-style attacks, as several of the attackers were based in Brussels.
France says 130 people died in a series of attacks in Paris. At least one suspected attacker is still at large.
The so-called Islamic State (IS) group says it carried out the gun and bomb attacks on 13 November. Five people in Belgium have been charged with terrorism offences in connection with the attacks.
In Brussels, schools reopened on Wednesday and public transport began running again from 06:00 (GMT) though some metro lines remained closed..
However, the city is expected to remain on its current top level of alert until at least next Monday.
Belgian Foreign Minister Didier Reynders said the authorities were looking for about 10 suspects who might have been be involved in planning attacks, possibly on shopping centres.
Meanwhile, it has emerged that Abdelhamid Abaaoud, the suspected ringleader who was killed in police raids in the Parisian suburb of Saint Denis, was near the Bataclan theatre during a deadly siege there.
French officials say Abaaoud was in a vehicle that dropped attackers off at a cafe and restaurants that were also targeted on the night of 13 November.
Prosecutors say there is evidence that Abaaoud was planning a later attack on the La Defense business district. According to French broadcaster BFM, Abaaoud and his accomplices had bought suits in order to blend in among workers in the area.
On Tuesday, an arrest warrant was issued in Belgium for a man named Mohamed Abrini over the attacks.
Prosecutors say that two days before the attacks, he was seen driving a car with suspect Salah Abdeslam at a petrol station on the motorway to Paris.
Abrini is described as "dangerous and probably armed". Abdeslam is currently the subject of an international manhunt after the attacks.
The Renault Clio that Abrini was seen driving was later used in the attacks, prosecutors say. Police say he should not be approached by the public.
In other developments:
Belgian media say the authorities thwarted a series of attacks that were due to have taken place in Brussels on Sunday
France's RTL radio reports that cafe, hotel and restaurant owners in Paris have appealed for government aid to help offset a drop in income following the attacks
Belgian prosecutors said on Tuesday that they had partially identified two men taken into custody as Ali O and Lazez A, both from the Brussels district of Molenbeek
French President Francois Hollande is due to meet German Chancellor Angela Merkel on Wednesday, as part of a diplomatic push to address the threat from IS.
On Tuesday, Mr Hollande met US President Barack Obama in Washington, while on Thursday he is scheduled to meet Russian President Vladimir Putin.
Mr Obama said there would be increased co-operation with France to hit IS targets in Iraq and Syria. He also called on the EU to implement an agreement that would require airlines to share passenger information in order to track suspected militants.