Powerful wildfires in US state of Alaska

Video caption, Huge flames and thick smoke are spreading across Alaska

Teams of firefighters and special aircraft are working around the clock to try to put out huge wildfires that are raging across parts of Alaska.

The state is the biggest in the US.

The Forestry Division says the fires were started by ''human activity'' but it's unclear if they were accidental or deliberate. They say the specific cause is still under investigation.

Many people have had to move out of their homes.

Some houses have been ruined and huge areas of land have been destroyed.

Dog teams at risk

Video caption, Teams are rescuing packs of dogs who live and work in Alaska after massive wildfires started to spread

40 miles north of Anchorage is where the Iditarod, Alaska's famed sled-dog race, typically kicks off.

Listen to this man talking about the efforts to make sure the teams of dogs living and working there, stay safe.

How did the fires start?

Video caption, Firefighters talk about how the wildfires in Alaska started

There are many separate fires in different areas.

Water-scooping aircraft and helicopters with water buckets have joined hundreds of firefighters to try to stop the fires spreading further.

There has been a late spring heat wave after record breaking temperatures in May.

There have been lots of thunderstorms.

Image source, Reuters

Image caption, Wildfires destroy trees in Willow in Anchorage, USA

Alaska Govenor Bill Walker says, '' It's pretty powerful. The fire itself is very powerful but the human response has been, I think, equally powerful to me.

To fly over and see what's been burnt and what's been left boy, we are so sorry about the losses of structures that have taken place.

I'm very pleased there has been no loss of life, I know we've lost some animals in the process and that's most unfortunate."