MONTEREY COUNTY (CBS SF) – The River Fire continued to tear through rugged terrain south of Salinas on Thursday after the lightning sparked wildfire doubled in size overnight.

As of 7 a.m. Thursday, Cal Fire said the fire has scorched 33,653 acres (52 square miles), up from 15,050 acres at 7 p.m. Wednesday and up from 10,000 acres on Wednesday morning. The fire’s containment is at 7 percent.

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Six structures have been destroyed, two others have been damaged. Meanwhile, the number of structures threatened has reached 2,750. Numerous evacuation orders remain in effect.

Fire crews maintain a backburn to control the River Fire near the Las Palmas neighborhood in Salinas, Calif., Wednesday, Aug. 19, 2020. (AP Photo/Nic Coury)

Cal Fire said the fire continues to burn in all directions.

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“High temperatures, low humidity, topography influenced winds, steep mountainous and difficult access continue to hamper firefighting efforts,” the agency said in its morning update. “Wind patterns differ on each side of the fire, which contributes to the spread of the fire in multiple directions.

More than 900 personnel have been assigned to the River Fire, including crews from the Bay Area. Four firefighters suffered minor injuries.

The fire was first reported at 3 a.m. Sunday, as a powerful and rare lightning storm passed through Northern and Central California, sparking numerous wildfires throughout the region. Containment is not expected until August 30th at the earliest.

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Meanwhile, crews are also battling another out of control wildfire several miles away. The Carmel Fire burning east of Carmel Valley Village has burned 4,286 acres and is zero percent contained as of Thursday morning, Cal Fire said.