Man injured in fall from Perth building

A man has been rushed to hospital with serious injuries after falling from the third floor of a Perth building as police investigated an alarm he appears to have activated.

Police said the 32-year-old man had climbed out of a window while they were searching a Howard Street building at about 2.45am, and was having trouble holding on and lost his grip, falling about 10 metres.

Police are looking into why the man was inside the building, saying there was substantial damage to glass panels, doors and furniture in several rooms.