Police uncovered a small marijuana grow operation in an apartment in St. Eustache when a suspicious fire engulfed the building it was in.

Police say the target of the fire was the neighbourhood bar Chez Aube. A witness saw flames coming from the bar, and three men running from the scene around 5:30 a.m. and called police.

There were traces of accelerant at the scene, but police are not sure why the bar would be targeted.

About 60 firefighters from 4 municipalities were called to the fire. The building will have to be destroyed.

Police say there were fewer than 50 plants in the grow operation.