The government of the Northwest Territories says an old mine site near Yellowknife needs better security.

Last week, firefighters put out a fire that had been set at the old Treminco Ptarmigan mine near the city. Burnt up propane tanks and other debris were found.

"Over the past few years there have been fires there," Yvonne Doolittle of Municipal and Community Affairs said. "There has been other type of activity — some mischievous  —  and some …people are out recreating, so I don't think people are fully aware that that is a contaminated site and that people should not be trespassing and going on that site."

Doolittle says the territorial government will set up boulders to prevent road access to the mine.

She also says health and safety warning signs will be posted for hikers. The territorial and federal governments are trying to figure out a plan to clean up the site, but they don't know just how polluted it is.

Treminco abandoned the Ptarmigan mine in the late 1990s.