A mysterious act of vandalism has been causing power outages and oil leaks on the North Shore. Someone has been tampering with dangerously high-voltage transformer boxes, but neither BC Hydro nor the RCMP know why.

"I'd like to understand what it is they want to get out of this. They are playing a dangerous game," said Jonathan Knowles, BC Hydro's public safety lead. "No indication of theft whatsoever; this is just pure vandalism."

The vandal has not been stealing anything from the power boxes. Instead, the perpetrator has been cutting into the boxes, putting them and others in danger.

The transformer boxes are packed with 12,000 volts of electricity, compared to a regular light bulb that has 125 volts. According to North Vancouver Fire and Rescue, one of the biggest dangers of tampering with a transformer is electrocution, followed by the possibility of starting a fire or even causing an explosion.

"If you see a transformer box that looks like it's been tampered with, you want to keep at least 10 metres away, call 911 and let our fire personnel arrive and access the scene," said Brian Hutchinson, fire chief at the District of North Vancouver Fire and Rescue Services.

Four damaged boxes have been replaced since April, which cost BC Hydro $150,000. The RCMP are investigating and are asking people to report any suspicious activity.

With files from CTV Vancouver's Emad Agahi