A 12-year-old Calgary boy has been charged with sexually assaulting three younger boys aged six, four and two.

Calgary police were called to a southwest home just before 10 p.m. MT on Tuesday on a report of a sexual assault.

The youth was arrested, and police found the three alleged victims inside the home. All the boys are residents of the home and are known to each other.

In what police are calling a rare case, the youth has been charged with three counts of sexual assault and three counts of sexual interference.