Ontario's Special Investigations Unit is investigating after police fired shots during an altercation with an armed man about 150 kilometres southwest of Ottawa.

Ontario Provincial Police say officers responded to a call at a home on Arden Road at Crotch Lake in Central Frontenac Township at about 5 p.m. Thursday.

When the officers from the Perth detachment arrived, an armed man confronted them, police said.

Police fired shots and the man, 45, was struck and taken to hospital with serious injuries.

The man underwent surgery, the SIU said, and he is currently recovering at Kingston General Hospital in serious condition.

The SIU is investigating, which it does whenever police actions in Ontario result in serious injury, death, or allegations of sexual assault.

There are five investigators and two forensic investigators assigned to the case, with eight officers identified as part of the investigation.

Anyone with information about the case is asked to call the SIU at 416-622-1935 or 1-800-787-8529, ext. 1935.