Updated: Police say a man has exited the residence and was taken into custody without incident.
Tactical officers remain of scene to clear the residence.
Original: Greater Sudbury Police were called to a weapons complaint near Madison Avenue and Christina Drive resulting a heavy police presence in the area Thursday afternoon.
Police said via twitter that a containment area has been established and it's believed the suspect is inside a residence. Residents are asked to avoid the area and remain inside their homes.
This story will be updated as information becomes available.