Police say a man blew his hand off while mixing homemade explosives in a Southern California home that doubled as a pot farm and a child care center.

Riverside County sheriff's Sgt. Dennis Gutierrez says a hospital contacted authorities late Wednesday to report a patient with a hand injury. Authorities responded and investigated the home of 23-year-old Benjamin Kuzelka. Gutierrez says they found more explosives, a sophisticated marijuana growing facility and evidence that the home had recently been used as a state-licensed child care facility. Authorities are investigating what type of explosives were being mixed.

No children were home at the time of the explosion.

The FBI and Los Angeles Police Department are assisting in the investigation.