A 39-year-old Oshawa man suffered multiple stab wounds after police say he confronted thieves who tried to steal marijuana plants from his backyard.

According to police, on Saturday at around 3:45 a.m. the owner of a home in the area of Ritson Road South and Olive Avenue noticed a motion light turn on in his backyard.

When the man went outside to investigate, police say he confronted two masked males who were trying to steal marijuana plants from his yard.

The homeowner sustained multiple stab wounds during the altercation and the suspects fled the area in a waiting vehicle.

The victim was taken to a Toronto trauma centre for treatment and his injuries are believed to be serious but not life-threatening.

Several plants, which were being legally grown, were taken from the property, police say.

The first suspect has been described by investigators as a white male who is five-foot-six and has a slender build. He was seen wearing a black hooded sweatshirt, brown pants, and black and white running shoes.

The suspect is believed to be a white male who is five-foot-nine with a medium build and was wearing a black hooded sweatshirt, blue jeans, gray shoes, and was carrying a backpack.

Anyone with information about the suspects or the case is asked to contact police or Crime Stoppers anonymously.