The IOPC said police officers had fired Tasers during the stand-off before a firearms officer shot and killed the man.
A spokesperson for the police watchdog said it had seized a knife from the property and would be examining police weapons and reviewing footage.
The spokesperson said West Mercia officers involved had provided initial accounts of what happened.
IOPC director of operations Steve Noonan said his staff would “independently investigate” all the circumstances around the man’s death.
“While police shootings are thankfully rare, it is understandable that people will be concerned when it does happen, and it is important we conduct a detailed and robust investigation into what took place,” he added.
