Brussels Mosque Alert Powder Turns out to Be Flour

Belgian emergency services evacuated the biggest mosque in Brussels and decontaminated 11 people on Thursday after the discovery of a suspicious package containing what turned out to be flour, officials said.

With the EU capital on its highest terror alert, firefighters in chemical suits and gas masks were called in to the Great Mosque of Brussels amid fears that white powder in the package could be anthrax.

"It was just flour. Everything is negative, the cordon has been lifted," Brussels fire brigade spokesman Pierre Meys told AFP after the mosque was sealed off for three hours, adding that the substance had been analysed at a laboratory.

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.

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.

Fire brigade captain Anne Wibin, who was at the scene, said eleven people, including two police officers, were decontaminated as a precautionary measure after the package was found.

"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," she said earlier.

"People in direct contact were isolated and decontaminated and also those who were in indirect contact."

Meys, the spokesman, said that four people were taken to hospital.

A worshiper said the development was worrying given the tensions after the Paris attacks which left 130 people dead when Islamic State jihadists, several of them residents of Brussels, went on the rampage.

"I've been speaking to the staff on the telephone and was told the imam found the package," said Mohamed Dahmichi, standing across the street.

"It's not good. With everything else happening in Brussels at the moment I'm afraid to leave the house these days.

"There was the letter at the mosque in Molenbeek too and now this," he added.

Earlier this week several mosques in the Molenbeek neighborhood, seen as a hotbed of jihadist activity inspired by IS, received threatening letters from a group calling itself "Christian state".

The Great Mosque, given as gift by Belgium to Saudi Arabia in 1967 which then carried out reconstruction work, 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 meters (yards) 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 when the city was put on top security alert.