Five days at the maximum alert level have come to an end in the Belgian metropolis. The announcement follows a false alarm involving a package of flour at a mosque in the city.
OCAM, the organization that assesses threat levels in the country, said on Thursday that the terror alert was being lowered from Level 4 - the highest level - to Level 3.
Brussels has been living under partial lockdown since Saturday as investigations into the terror attacks in Paris on November 13 began pointing towards Belgian citizens and residents.
"The situation is serious, but according to indications from the security services, not as imminent as previously assessed," said Belgian Prime Minister Charles Michel.
While there will still be a police presence on the streets, the metro and schools, which were partially reopened on Wednesday, will begin operating as normal on Friday.
"This is good news for social life and mobility in Brussels, but this is not over, it is only a start," Rudi Vervoort, head of the Brussels regional government, told Belgian news agency Belga.
Police are currently searching for Salah Abdeslam, a key suspect linked to the attacks. Earlier on Thursday, they launched a raid in the southern part of Belgium, but no arrests were made.
Investigators arrived at Brussels' Grand Mosque on Thursday following the discovery of a suspicious package containing white powder resembling anthrax, which authorities have since confirmed was flour.
The patron who found the package immediately called the police, prompting firecrews and decontamination teams to be deployed to the scene.
Anne Wibin, captain of the city's fire brigade, told reporters earlier in the day that even though the substance had not been found to be radioactive, authorities were still going through with the investigation.
Eleven people who were in the mosque at the time underwent decontamination as a precaution, she said.
blc/msh (AFP, AP, Reuters, dpa)