The Lethbridge Police Service (LPS) says the incident involved a man barricaded inside an apartment building on the 2500 block of Walsh Drive West.
Police are currently surrounding the building, and have blocked a vehicle in the parking lot.
Witnesses say police arrived shortly after noon and have been at the scene all afternoon. The LPS K-9 unit is also at the scene and police are reportedly using a drone to monitor the scene.
This is a developing situation and Lethbridge News Now will provide more information as it becomes available.
READ UPDATE: High-risk incident ends, one person arrested