Toronto police are investigating a robbery of the city's most famous house.

Casa Loma was broken into Saturday between 2 a.m. and 4 a.m., police say.

Three antique weapons that were on display -- a rifle, a sten gun and a bren gun -- were stolen as well as a helmet from the Queen's Own Rifles exhibit.

Police say they believe there is more than one person involved in the robbery.

The suspects used scaffolding outside the castle to access a second storey window. The window was smashed and there was minor damage inside the property, Det. Const. Bryan Campbell told

Campbell said detectives are investigating whether or not the exhibit was targeted by the thieves.

"We can't say if their intent was specific to get those items," he said.

The weapons are non-operational and the value of the property seized is about $3,000, Campbell said.

Police found blood stains at the crime scene and were able to trace it back down the scaffolding, north on Spadina Road until St. Clair Avenue.

Campbell said the perpetrators likely injured themselves when they smashed the window and that the injury is likely significant.

"For the blood trail to carry on that long, you would think (the injury is serious)," he said.

Police are asking anyone who may have noticed something suspicious to give them a call at 13 Division, 416-808-1300. Anonymous tips can also be left with Crime Stoppers at 416-222-TIPS.