LOS ANGELES, Aug. 21 (Xinhua) -- An aggressive wildfire burning in Glacier National Park near the U.S. - Canada border expanded by strong winds from the northeast, burning over 11,172 acres (45.2 square kilometers) as of Tuesday morning.

Officials of the park said Tuesday morning that the fire, dubbed "Howe Ridge Fire" which started on Aug. 11, grew by nearly 13 square kilometers from Saturday night to Monday night.

The authority explained that even though Monday's variable showers and cooler temperatures moderated fire behavior and aided in firefighting efforts, but in the evening and overnight, driven by down-valley winds, the fire burned actively after winds pushed it into pine trees killed by a 2003 fire.

The lightning-sparked fire has burned 13 homes and 14 other structures in the park and has cost 1.8 million U.S. dollars to fight. There have been no reported injuries, however, there is also no containment at this point.

Due to the heavy smoke from the fire, the Montana Department of Environmental Quality issued an air quality alert Sunday for 56 counties, including all of western Montana and the counties surrounding major cities like Helena, Butte and Billings.

Glacier National Park is a over 4,000 square kilometers wilderness area in Montana's Rocky Mountains. It was designated by the United Nations as World Heritage site in 1995.