A massive wildfire pushed by wind in Alaska's Kenai Peninsula south of Anchorage continues to explode in size, leading to mandatory evacuations of 1000 structures, officials say.
The number of people told to flee their homes isn't clear, said Michelle Weston, spokeswoman with the Alaska Interagency Management Team, which includes the state Division of Forestry and federal and local officials.
She said the fire recently covered nearly 565 sq. kilometres and has grown significantly as it burns in the 770,000-hectare Kenai National Wildlife Refuge, but she didn't immediately have a new estimated size.
The Funny River Fire is named after a nearby road where all residents are being evacuated. She says Alaska State Troopers are going door to door, evacuating an area that's mostly second homes and is home to many retirees.
She says no injuries were reported, and it's unclear if any buildings were damaged.
She said erratic fire behaviour driven by high winds and extremely dry conditions allowed the flames to grow.
Earlier Sunday, the fire spanned 500 sq km and was 20 per cent contained.
The size of the blaze is not unusual for Alaska but the state does not usually see such large fires this early in the season, Weston said.
She said spot fires jumped over the Kenai River close to the community of Sterling, and officials were evaluating the changing conditions to see if the flames threatened structures there.
Crews were attacking the fire by air, with two Alaska Air National Guard helicopters and five other helicopters involved, Weston said.
Brenda Ahlberg, spokeswoman for the Kenai Peninsula Borough, said a Red Cross shelter was being set up for evacuees.
The Alaska Department Natural Resources warned residents of Anchorage, the state's largest city, to expect to see considerable smoke from this and another wildfire.
The Funny River Fire is the most active of several large wildfires burning in Alaska. Firefighters have been flown in from Oregon, Montana and Canada to help Alaskan crews.
Governor Sean Parnell flew over the fire at midday on Sunday, before the wind-driven expansion. He praised the multiagency effort - including state, local and federal officials.
Wildfires in Alaska's remote areas are not unusual during the summer months, with an average of a million acres burned each fire season, Weston said.
The state is experiencing unusually dry conditions because of unseasonably warm spring temperatures. High wind is also a challenge for crews.
The Kenai National Wildlife Refuge was established in 1941 as the Kenai National Moose Range and was aimed at moose protection. Wildlife viewing, fishing, camping and hiking attract visitors from around the world.