"The madness of men is what it is but peace must win over."
The statement from prosecutors said the investigation "is continuing actively day and night.''
The report said two of the men were known to police.
"It’s pretty crazy to think that we would have been a part of that."
Belgian officials said the casualty toll from three explosions in the capital was 26 dead and at least 136 injured.
Belgium raised its terror alert to its highest level.
Twenty-three students from Sir Charles Tupper Secondary and their chaperones were in Ghent, about 35 kilometres outside Brussels.
Officials from Quebec's government office in Brussels strongly suggested he remain in the hotel for the rest of the day.