Canada's Defense Ministry said the vast majority of the sites have not been inspected and are "suspected" of having leftover explosives only because historical records or first-hand accounts given to the department suggest the possibility, the Toronto Star reported Monday.
Jon Preston, operations manager of the Defense Ministry's Unexploded Explosive Ordnance and Legacy Site program, said his office is charged with investigating where explosives were manufactured during World War II and where they might have been buried.
The ministry said 15 people have been killed and 20 injured since 1927 by explosives buried in the ground.
The issue is coming to the forefront now because many of the bomb ranges and manufacturing sites that were once stationed in remote areas are now being developed as the nation's population increases.
The Canadian government has spent $70 million since 2005, when the ordnance unit was established, seeking to identify and clear suspected sites, the Star reported.