INTERNATIONAL FALLS, Minn. (AP) -- A wildfire caused by a lightning strike at Voyageurs National Park earlier this month has grown to 331 acres, the National Park Service said Sunday.

The fire began July 8 between Shoepack and Loiten lakes in the park, which is on the Canadian border near International Falls.

On Saturday, the National Park Service reported 220 acres on fire, but then revised its estimate based on increased fire activity and a remapping of the fire perimeter.

The fire is burning through jack pine, balsam fire and spruce trees.

The park remains open, but some trails and lakes are closed.