Brussels will stay on the highest level of terror alert today amid a manhunt for suspects linked to the Paris attacks.
Belgian Prime Minister Charles Michel said the rest of the country will remain on a threat level of three on a four tier scale.
Brussels has been on lockdown all weekend, as police search for suspected Paris attacker Salah Abdeslam.
Schools, universities and the metro in the Belgian capital will remain closed on Monday.
"What we fear is an attack similar to the one in Paris, with several individuals who could also possibly launch several attacks at the same time in multiple locations," Mr Michel told a media conference in Brussels.
Possible targets were malls, shops and public transport, Mr Michel said, adding the government would boost police and army presence in the capital.
Belgium has been at the heart of investigations into the 13 November Paris attacks - a series of co-ordinated bomb and gun attacks which left 130 people dead - after links to Brussels, and the poor district of Molenbeek in particular, emerged.
Fugitive suspected militant Salah Abdeslam, 26, slipped back home to Brussels from Paris shortly after the attacks, in which his elder brother Brahim blew himself up at a cafe.
Fears of the risks he still poses prompted the cancellation last week of an international friendly soccer match in Brussels against Spain.
Earlier, Belgian Interior Minister Jan Jambon said the danger to Belgium was not tied to Salah Abdeslam alone. "The threat is broader than the one suspected terrorist," he told Flemish broadcaster VRT.
Soldiers joined police officers on patrols in Brussels over the weekend. Many public spaces in the usually bustling capital were deserted, as people heeded official warnings to avoid crowds.
- Reuters / BBC