A trap has been set up in a regional park in B.C.'s Lower Mainland due to what officials have described as "extreme bear activity."

Metro Vancouver Regional Parks said the trap will be used to capture an aggressive bear known to be in the area of Lynn Headwaters.

A conservation officer said there were multiple reports it had been following people and chasing dogs. This morning, it chased a lone runner who had to enter a building to get away.

"I can tell you it's a smallish bear that looks very healthy," BC Conservation Officer Service Sgt. Simon Gravel said Thursday.

While there are always bears in the area, this particular bear is exhibiting concerning behaviour, he added.

"When a bear reaches this level of conflict where he's food conditioned and extremely habituated to people, has some predatorial-type behaviour, we're very limited in options. So unfortunately, this bear, if he's captured, he will be euthanized," Gravel said.

Earlier in the day, MVRP announced that two trails had been closed in the park. Varley Trail and Connector Trail were both reopened in the afternoon, after the trap was set, but the area remains under alert.

A bear alert is also in place for the Lynn Loop Trail, they said, and it is best if the public avoids the area.

"The important message here is to remind everyone to use backcountry area or these kind of parks with a lot of caution," Gravel said.

It's best to hike with at least one other person and make noise while walking, officials said. People heading into the trails should also carry bear spray and keep dogs on leash.

Those who encounter wildlife are advised not to attempt to get close or feed the animal.

Hikers are also advised to stay calm, and not to run, but instead to make themselves as big as possible. Face the bear and back away slowly, shouting or speaking loudly in a confident voice, Metro Vancouver advised.

A cougar has also been seen in the park a number of times over the summer months. Officials offered similar advice, and added small children should be picked up, as their frightened movements can provoke attacks.

The young black bear is believed to be the same one that killed a dog earlier this month. The dachshund was off-leash in the upper portion of the Lynn Loop at the time.

Hikers used a whistle to scare the bear away from the dog, but it did not survive.