Belgium has lowered the security threat level in Brussels after nearly a week on maximum alert following the Islamic State attacks in Paris.
Confirming earlier reports, Kris Peeters, the economy minister, told public broadcaster VRT that the national threat assessment agency, made up of security experts and officials, had taken the decision.
The government's national security council was meeting to discuss concrete measures to be taken.
The reduction to Level 3 - serious, a possible and probable threat - from Level 4 - a very serious, "imminent" threat - brings the capital into line with the rest of the country.
Immediately after the Paris attacks on November 13, Belgium raised its security alert to Level 3 and a week later put Brussels onto maximum alert as police hunted a local suspect in the violence in France as well as accomplices who the government said might be planning similar attacks in the Belgian capital.
The suspect remains at large. Police have mounted a number of raids and searches over the past two weeks in Belgium and have charged five people with terrorism offences linked to the Paris attacks.
On Thursday (local time) firecrews and decontamination teams also attended a major mosque in Brussels close to the European Union headquarters to investigate a suspect powder that police later said turned out to be flour.
Reuters journalists saw about a dozen emergency vehicles, including police, outside the Islamic and Cultural Centre of Belgium, a large Saudi-established institution including a mosque situated 200 metres from the European Commission.
A spokeswoman for the fire service said it had taken a call from the mosque from a person saying they believed that they had found anthrax powder, prompting the deployment of specialist crews. A police spokesman later said the substance was flour.
There have been reports of threats against mosques used by Belgium's half million Muslims in the past two weeks, among them some from an unknown group calling itself Christian State.
By Danny Kemp
The Great Mosque of Brussels has been evacuated and 11 people decontaminated after the discovery of a suspicious package containing white powder as the EU capital remained on highest possible terror alert.
"A parcel was found at the entrance to the mosque and found to contain white powder. We are taking all preventative measures in case it is anthrax but it is a precautionary measure," said fire services spokeswomen Anne Wibin, who was at the scene on Thursday (local time).
The mosque, the city's biggest, is located just a few blocks from the major EU institutions and many embassies and was cordoned off by police and firemen, some of them in white hazard materials suits.
The alert came with Brussels on maximum security levels in the wake of the Paris attacks on November 13, with two Belgium-linked suspects still on the run.
Wibin said eleven people, including two police offers, were decontaminated as a precautionary measure.
"A package was found with several envelopes one of which contained a powder, evidently suspect in the circumstances," she said.
"The powder has been partially tested and it has been found to be not radioactive," she said, adding that no possibility was being ruled out.
"People in direct contact were isolated and decontaminated and also those who were in indirect contact."
"There is absolutely no danger to anyone," she added.
The Great Mosque, given as gift to Saudi Arabia by Belgium, sits on a corner of Cinquantenaire Park where many of the thousands of EU staff take a lunchtime break and families bring their children to play.
It is no more than 200 metres from the top EU institutions - the European Council and the European Commission - plus other offices and many embassies.Troops and armed police have been out in force in Brussels since Saturday, with the authorities due to review the top level four security alert on Monday.