CALGARY -- Two brazen home invasions in three days at a Mountie's house left his girlfriend unconscious from a head injury and cops vowing to catch the thugs responsible before they strike again. Canmore RCMP Const. Norm Weber wasn't home during the incidents, which occurred during the early morning hours last Tuesday and again on Thursday.

In both cases two men burst into the home using force in search of the officer. The first time they fled when the woman inside told them police had been called. "She didn't actually see the suspects that time," said RCMP spokesman Cpl. Wayne Oakes.

On Thursday, she caught a glimpse of the two when they threw a huge rock through the glass section of the front door.

It hit the victim in the head, knocking her out and when she came to, the assailants asked for Weber.

When she told them he wasn't home, the pair fled.

"She was knocked for a loop, so her ability to get much of a description was extremely limited," Oakes said, adding the victim told cops the men are average height and weight.

The woman was taken to hospital and treated for a non-life-threatening head injury.

RCMP and Calgary Police Service detectives who are probing the matter don't know why Weber has been targeted or how the men got his home address.

"On the surface, there doesn't appear to be a reason but part of our investigation is to look back at the investigations, charges and files this member has been involved in to see if there's anything that in someone's mind might warrant this behaviour," Oakes said.

Oakes said cops face numerous dangers on the job but they're typically not targeted outside of work.

"Something like this is extremely rare," said Oakes.

"For them to do it twice is even more rare."