Image copyright Getty Images Image caption Evacuations continued as the Holy Fire approached within a half mile of homes on Wednesday

Authorities have arrested a man for starting the so-called Holy Fire, which has burned over 9,600 acres through the mountains of Southern California.

Forrest Gordon Clark, 51, had emailed the local volunteer fire chief to threaten "this place will burn", according to Orange County officials.

Over 600 firefighters are battling the Holy Fire, which is just one of 18 wildfires raging across the state.

The Mendocino Complex fire has been declared the largest in state history.

Image copyright Police handout Image caption Forrest Gordon Clark, 51, is accused of starting the fire after a decade-long dispute with his neighbours

Media playback is unsupported on your device Media caption With wildfires occurring across the globe, here are some of the techniques used to stop them

Mr Clark was arrested outside his cabin on Tuesday after a brief standoff with officers.

He was charged with arson, felony threat to terrorise and resisting arrest.

Image copyright Getty Images Image caption Evacuees watch flames crest over the nearby mountains

He was booked in jail on a $1m bond in relation to the fire, which continues to burn in the Santa Ana Mountains south of Los Angeles.

Authorities say he intentionally started the fire on Monday after a decade-long dispute with neighbours.

Image copyright Getty Images

All 12 nearby properties were burned by the fire, with only Mr Clark's home left standing.

Susan Schroeder, spokeswoman for the Orange County district attorney's office, said her office would "bring him to justice for these terrible crimes".

More than 600,000 acres across the state have been consumed by this year's fire season, which experts warn is growing longer each year.

More than 14,000 firefighters are working across the state, with crews from Australia and New Zealand assisting.

Prisoners, including fewer than 100 juvenile offenders, are also lending a hand in exchange for only a few dollars a day.

Two firefighters have been treated for heat-related injuries in the Holy Fire.

Officials say that fire is only 5% contained as temperatures continue to stay above 90F (32C).

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But they are hopeful that weather conditions will improve when temperatures fall over the weekend.

Meanwhile, evacuations continued on Wednesday as the Holy Fire flames approached within half a mile of homes.

'Biggest in history'

The Mendocino Complex Fire in northern California, which is made up of two separate fires, has burned at least 302,086 acres since it began on 27 July.

The area of destruction is now larger than the entire city of Los Angeles.

Authorities say it is only 47% contained, and predict that it will continue to burn into September.

The second largest is the Carr Fire, which has burned more than 176,000 acres, and has killed seven people and destroyed more than 1,000 homes.

According to state fire officials, California's fire expenses have more than trebled from $242m in 2013 to $773m in the 2018 fiscal year ending on 30 June.

Wildfires are also burning in British Columbia, Canada, where reinforcements have arrived from Mexico and New Zealand to help combat the outbreak.