Fires threaten world's oldest trees

Huge fires in and around California's Yosemite National Park have continued to spread and now cover an area the size of Edinburgh.

The fires have been burning uncontrollably for more than a week.

Drought conditions and high temperatures helped the flames spread quickly through the trees and the bush.

More than 3000 firefighters are still trying to control it, creating defences lines with controlled burning to stop more devastation.

Ash is now raining on a nearby reservoir that supplies water and hydro-electric power to the city of San Francisco.

Officials say they're moving water to lower reservoirs and checking on supplies for pollution.

The blaze is also threatening thousands of homes and some of the oldest trees on earth.

California Governor Jerry Brown has declared a state of emergency for San Francisco 150 miles away as the blaze is also threatening power lines that bring electricity to the city.

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