Calgary Police have arrested a man in connection with the murder of two children found dead in a home in the northwest part of the city.

When police entered the home on Friday night after receiving a frantic 911 call, they found the bodies of a 13-year-old boy and a nine-year-old girl.

Calgary Police Chief Rick Hanson told reporters Saturday that after officers found the bodies, they continued searching the home, "and came upon a man and a woman in the upstairs portion of the home. Both were involved in a physical struggle and officers immediately intervened."

Police said a woman, reported to be the children's mother, was the first to stumble on the crime scene.

"The preliminary information indicates that she had arrived home and that's where the first contact was made with the police," Insp. Guy Slater of the Calgary Police Major Crimes Unit said at a Saturday news conference.

The woman was taken to hospital where she was treated for minor injuries. Officers arrested the man.

"It is our firm belief that the rapid intervention of our officers interrupted a potential homicide," said Hanson.

It's a crime that has shocked the community that's popular with young families.

Neighbours told CTV Calgary that up to three children, including two teenagers, live at the address.

With a report from CTV Calgary