A bear is believed to have attacked and killed a 33-year-old hiker who had gone missing in the Glacier National Park in Montana since Sunday, officials say.

Search and rescue crews spotted the hiker's remains in a densely wooded area, with injuries "consistent with those sustained by a bear encounter".

Officials identified the hiker as Anthony Pollio from Fort Lauderdale, Florida. The National Park Service has closed the part of the trail where the body was found.

Fatal bear attacks are rare in the US, but experts say the animals grow bolder and lose their fear of humans when homes and campgrounds become easy food sources.

Glacier National Park has been referred to as "bear country" due to its dense population of grizzly bears (known as brown bears). Black bears are also common in the area.