Death threat sent to Attadamoun Mosque in Molenbeek, home of Paris attack suspects.
The Paris killers were linked by drug-dealing, drink and petty crime, not religion.
Belgian authorities investigate a suspect powder that police later said turned out to be flour.
Schools and the metro have reopened in the Belgian capital.
Belgium issued a warrant for a new suspect on Tuesday.
Salah Abdeslam, suspected gunman in the Paris attacks, remains at large, Belgian authorities say.
Authorities put Brussels on maximum alert, closing the metro system, along with museums, shopping centers and other public spaces.
Authorities warned people to avoid crowds, raising the threat level to four.
The government will increase police powers for raids and house arrests.
Manuel Valls says French authorities "must not rule anything out" after Paris attacks.
The operation focused on friends and family of suspect Bilal Hadfi
The search continued for Salah Abdeslam and others thought to be responsible.
On Friday, the Brussels resident blew himself up in Paris on orders from ISIS.
The arrests were related to a vehicle with a Belgian number plate.
The bank has been accused of helping its customers to 'dodge millions in tax'
The raids were not linked to the recent deadly militant attacks in Paris, prosecutors said.
The country will debate an anti-terror package next week as European countries step up their security.
The battle between jihadis and security forces in France may soon become brutal.
Anti-extremism thinktank warns of huge number of European jihadists returning home after fighting for ISIS.
There were arrests in Paris, Berlin, Belgium and Austria today after two were killed in a raid in Belgium last night.
Some Jewish schools in Belgium and the Netherlands were closed, reflecting a heightening tensions in Europe.
The siege ended about 1pm after three men surrendered themselves to polic
French, Italian and Belgian draft budgets for 2015 may be at risk of breaking rules says European Commission