Several spot fires broke out along along Wildcat Canyon Road Tuesday, threatening some structures and promoting a quick response from Cal Fire crews.

Helicopters and ground crews jumped on the wildfires just afternoon along the winding road that leads to Barona Casino in San Diego's East County.

The largest fire was estimated to be approximately 10 to 20 acres in the area just northeast of the main gate to the casino. Inside, a spokesperson said it was business as usual.

Outside, fire crews requested Wildcat Canyon Road be closed from Founders Way to San Vicente Road to keep traffic out of the area while they knocked down the small fires.

As of 12:39 p.m., Cal Fire said there were no evacuations. No structures were damaged and there were no injuries.

At the command post, officials said the fires started almost simultaneously. No cause has been determined.

Weather in the area at the time the fires sparked was nearing 90 degrees but with calm winds recorded at less than 4 mph.

Images: Wildcat Canyon Road Wildfires

At the same time, an explosion and fire were reported at Brown Field near the U.S.-Mexico border. The structure fire on Continental Street sent thick, black smoke into the air over the South Bay.

With the statewide drought, fire conditions are more dangerous than in previous years.

Cal Fire crews have fought 600 more wildfires in the state of California than at this time in 2013.