A large swath of trails near Squamish, B.C., has been closed to users as conservation officers hunt down an aggressive cougar that's been stalking people.

Conservation officer Insp. Chris Doyle said three groups of mountain bikers encountered the cougar over the weekend on trails around Alice Lake, about 80 kilometres north of Vancouver.

In each case, Doyle said the animal was very difficult to scare off, and showed considerable interest in the humans.

Officers were on the trails over the weekend. On Monday they closed seven trails and brought out their tracking dogs.

"It's definitely of concern, the type of behaviour it's exhibiting and the fact that it has no fear of people and is approaching people -- on more than one occasion."

Starved cougars have been known to stalk humans, but Doyle said eye witnesses say this is a large, healthy-looking cougar.

"Normally humans aren't a prey source," he said. "They mainly are hunting deer and other smaller game, so there's a concern when they're approaching people."

The animal has been spotted in the Garibaldi Highlands, a residential community north of Squamish, and around Alice Lake Provincial Park. The trails that link the two areas have been closed.

Warning signs have been posted in the areas and Doyle said they are getting the information out to trail-user groups in the area not to use the trails.

If someone spots a cougar, Doyle said the worst thing to do is run because the animal's prey instinct kicks in.

"You want to face the animal, make yourself look big, make some noise, but never turn and run."

Last month, a Vancouver Island teenager was riding her bicycle down a road near Nanaimo when a cougar confronted her near an elementary school.

At first she tried to ride away, but when it began following her she turned and confronted the cougar, made some noise and slowly backed away until she made it to the school and used her cellular phone to call for help.