Fast-moving wildfires have left two U.S. firefighters critically injured and forced tens of thousands of residents in Orange County in Southern California to evacuate amid high winds on Monday.

One blaze dubbed "the Silverado Fire," which started Friday morning in the area of Santiago Canyon Road and Silverado Canyon Road, has exploded to more than 7,200 acres (29 square km) in hours, according to the Orange County Fire Authority.

A total of 500 firefighters are battling on the scene amid erratic winds that can reach up to 96 km to 112 km per hour. Officials said that air support has been grounded due to high winds.

According to the Orange County Fire Authority, two firefighters, aged 26 and 31, were critically injured fighting the blaze at noon. Both have second and third degree burns and are currently intubated in the ICU.

At least 60,000 people have been evacuated, said Christina Shea, mayor of Irvine City, in a release.

"We are asking everyone to comply with the evacuation orders for their safety and the safety of our first-responders. The City of Irvine continues to open care and reception facilities for our displaced residents," she noted.

Some roads and school campuses in the area were shut down due to the wildfire. Both Irvine Unified and Tustin Unified School District schools will be closed on Tuesday, according to the city's mandatory evacuations.

Video from the scene showed the area blanketed by heavy smoke and fires raging along roads.

A second blaze dubbed "the Blue Ridge Fire" started at noon and spread to 1,120 acres at zero containment as of Monday evening.

A total of 1,651 homes in the nearby cities of Yorba Linda, Hidden Hills and Chino Hills have been affected by the fire, including 1,170 homes under evacuation orders and 481 homes under voluntary evacuation, according to the Orange County Fire Authority.

At least 200 are battling the fire. Officials said that one home had been reportedly damaged by the blaze and were still waiting on further details.

Yorba Linda, the birthplace of former U.S. President Richard Nixon and home to the Richard Nixon Presidential Library and Museum, was among the buildings hit by the second wildfire.

"With nearby #BlueRidgeFire we are taking steps to make sure Yorba Linda's most famous building, the Birthplace of President Nixon, is protected," the Richard Nixon Foundation tweeted Monday afternoon, adding that "We will continue to monitor throughout the evening."

Video posted by the foundation showed staff spraying water at Nixon's former residence as precautions.

A total of 15,331 people at 4,688 homes were under mandatory evacuation orders in Chino Hills, according to Chino Valley Fire District, adding that an additional 2,850 people were under an evacuation warning.