Envelopes containing white powder were sent to a Brussels mosque but emergency crews who rushed to the scene said the substance was just flour, officials told NBC News. The Belgian capital has been on lockdown after officials warned extremists may be planning a Paris-style attack. Specialist units rushed to the city’s Grand Mosque after the envelopes were discovered there, fire brigade spokeswoman Malika Abbad told NBC News. Read the rest of the story from our partners from NBC News