Belgium remains on a high state of alert after Islamic State-claimed bomb attacks in March left 32 dead at the airport and on the metro.
Today's incident began at about 6:30 a.m. after a report of a man acting suspiciously near the City 2 shopping centre set off a bomb alert.
"The situation is for now under control. We remain vigilant," Prime Minister Charles Michel said after an emergency meeting of his security cabinet.
A bomb squad team was immediately deployed at the shopping centre, one of the main retail hubs of the Belgian capital.
"No bomb has so far been found. The suicide vest found on a suspect was fake," the Brussels prosecutors office said.
Only one exit remained open at the nearby Rogier metro station, where soldiers checked passengers bags and belongings.
Police and soldiers sealed off the immediate area, an AFP reporter on the scene said.
The incident comes only days after Belgian authorities charged three men with "attempted terrorist murder" after raiding dozens of homes linked to a reported threat to fans watching during a Euro 2016 football game.
Prosecutors charged the three men, named as Samir C, Moustapha B and Jawad B, but released nine others after questioning.
The areas searched included neighbourhoods in Brussels where November's jihadist attackers in Paris and the Brussels suicide bombings had planned their assaults.
Authorities said at the time they were responding to a need for "an immediate intervention".
Per capita, Belgium has the highest number of so-called foreign fighters in the EU who have travelled to wage jihad in Syria and Iraq, an estimated 500.
After Saturday's swoop, Michel said the country would be taking "additional and updated security measures."
However, he pledged that public events planned for the coming days would go ahead, including those linked to the Euro football championships in France.
"We want to continue living normally," the premier said.
Despite the lockdown in the area, the terror alert level in Brussels remained at level three out of four, Belga reported.
On Saturday, a source close to Belgian authorities confirmed to AFP that several leading political figures have recently had their security increased.