image sourceReuters

Tens of thousands of people have been evacuated from the shores of Lake Tahoe in northern California as a major wildfire continues to spread.

The Caldor Fire has already burned more than 191,000 acres, with just 16% of the fire brought under control.

More than 3,500 firefighters have been deployed to combat the blaze, which began more than two weeks ago.

One hospital has been forced to evacuate, with patients transferred to other facilities in the region.

Five people have been injured, while more than 700 properties have been damaged or destroyed, according to authorities.

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The 22,000 residents of the city of South Lake Tahoe, a popular holiday destination, and surrounding areas were issued with an evacuation order on Monday morning.

The US Forest Service has also announced the closure of all Californian national forests from late on Tuesday until 17 September because of the wildfires.

The Caldor Fire is one of seven blazes currently active in California. The largest, the Dixie Fire, has burned more than 800,000 acres since it broke out in mid-July, and is the second-largest in California's history.

media captionMost of the historic Gold Rush town of Greenville was destroyed in early the Dixie Fire

Climate change increases the risk of the hot, dry weather that is likely to fuel wildfires.

The world has already warmed by about 1.2C since the industrial era began and temperatures will keep rising unless governments around the world make steep cuts to emissions.