Giant redwoods: California wildfire threatens world's largest trees

Smoke plumes can be seen rising from the wildfire which started last week

Hundreds of firefighters in America are trying to control a raging wildfire in the famous Yosemite National Park.

The blaze, which has been named the Washburn Fire, started last week and could threaten at least 500 giant redwood trees - also known as sequoia trees.

The Californian national park is home to the some of the largest and oldest redwood trees in the world, including the famous 'Grizzly Giant' which is thought to be around 3,000 years old.

The wildfire has now been partially contained, however officials say that warm and dry weather conditions are making it difficult to control the flames.

What is being done to help?

The 'Grizzly Giant' is a popular tourist attraction in the Mariposa Grove in the national park, and is thought to be around 3,000 years old

More than 1,500 campers and residents living nearby have been evacuated from the area and parts of the park have been closed to the public.

Nancy Phillipe, from the Yosemite Fire Information, said that a lot of support was being provided to tackle the fire including help from ground crews, helicopters and air tankers which release thousands of gallons of water from the sky.

She added: "We are doing everything we can to put this fire out."

Giant sequoias can live for thousands of years, making them among the oldest living things on Earth.

They are also some of the biggest trees on the planet - they can grow more than 80 metres tall and more than 11 metres in diameter.

Officials say that more than 35,000 wildfires have burned across the US so far this year, which is well above average.

It's thought warmer temperatures and more extreme drought conditions caused by climate change are making wildfires more common.