After a tense week of Brussels on high alert and lockdown due to terror threats, the terror alert level was reduced from four - the highest - to three on Nov. 26. This news comes on the same day that the city's Grand Mosque, The Islamic and Cultural Centre of Belgium, was sent a suspicious envelope full of white powder that was confirmed to be flour, a false alarm.

The mosque was evacuated and shut down for three hours, and a chemical team was dispatched to the scene where 11 people were decontaminated and four taken to hospital as a precaution, Expatica reports. The powder was analyzed in a lab. "It was just flour. Everything is negative, the cordon has been lifted," said Pierre Meys, a Brussels fire brigade spokesman.

Since the terrorist attacks in Paris on Nov. 13, and due to some of the suspects being linked to Belgium, there have been threats against mosques all over Belgium, some from an unknown group called the Christian State, reports Reuters. There are half a million Muslims in the country.

Brussels, the capital of the EU and home to many embassies and EU institutions, has been patrolled and locked down since Nov. 21 in the wake of threats promising an attack similar to the terror that shook Paris. The mosque that received the white powder is located on Cinquantenaire Park, 200 meters (about 656 feet) from the European Commission, where many EU workers and their families meet for lunch breaks, reports Expatica.

"After a new evaluation by the Threat Analysis Coordination Agency the level has been lowered from four to three, meaning the threat is serious and credible," Prime Minister Charles Michel said at a press conference, according to Expatica. The threat was previously at level 4, for a serious and imminent threat. Michel explained that though the situation remains grave, the imminence of the threat is no longer present.

As of Wednesday, schools and some metro stations had been partially reopened, noted DW. The city will remain heavily patrolled by police.