TORONTO -- A grizzly bear attacked and killed two people and their dog in Alberta's Banff National Park, according to Canadian park officials and a friend of the victims.

Parks Canada said in a statement on Saturday night it had received an alert late Friday from a GPS device indicating a bear attack in the Red Deer River Valley west of Ya Ha Tinda Ranch in Banff National Park.

The bear was later euthanized after it displayed aggressive behavior, the agency said.

The victims were a Canadian couple and their dog, according to Kim Titchener, the founder of Bear Safety and More and also a friend of the family.

Titchener, who provides training on bear safety and bear assessments, said such encounters are increasing as more people head outdoors but fatal attacks are extremely rare.

"It's really just the reason why we're seeing more attacks, which is more people heading outdoors and unfortunately not being educated on this," she said by telephone, adding that only 14 percent of grizzly bear attacks worldwide lead to fatalities.

Bear sightings increase during autumn as they become more active searching for food ahead of hibernating in the cold winter months.

Banff National Park, which attracts more than four million tourists every year, is home to both grizzly and black bears.

There are about 60 grizzly bears in Banff National Park and are considered to be a threatened population in the Alberta, Titchener noted.

Parks Canada said its rescue team had to travel by ground through the night to the location as weather conditions at the time did not allow for helicopter use.

The response team arrived on-site during the early hours of Saturday where they discovered two deceased individuals, the agency said.

An area closure around Red Deer and Panther valleys has been implemented and will remain in place until further notice, Parks Canada said.

Parks Canada did not immediately respond to queries on identifying the victims.