Police received a call around 3 a.m. reporting the man had barricaded himself in an apartment building.
The weapon allegedly in his possession is described as a long-range gun.
About 10 other residents from the building were rushed out by police officers attending to the scene.
Nearby businesses were also evacuated.
Officers are still trying to contact the man inside the apartment, but report that he is not shooting or threatening anyone.
A large security perimeter has been set up around the building. The northbound Thibeau Boulevard is closed near the corner of Des Prairies Street.
The Quebec provincial police have taken over the operation from the local Trois-Rivières police force.