LOS ANGELES, July 4 -- At least 28,000 people are under evacuation orders as a fast-moving wildfire continued to burn on Thursday in Northern California amid severe heat wave.

According to the California Department of Forestry and Fire Protection (Cal Fire), the Thompson Fire, which erupted on Tuesday near the City of Oroville in Butte County, had already consumed over 3,700 acres (about 15 sq km) of land as of Thursday noon, with only 7 percent containment.

At least four structures were damaged by the blaze and four firefighters were injured while battling the wildfire. Over 12,000 structures in the area are threatened, according to Cal Fire.

More than 1,900 firefighters are currently fighting the wildfire, continuing to strengthen containment and control lines.

Cal Fire officials said in an update that they are expecting high temperatures increasing the chances for fire growth on Thursday, adding that firefighters on the line will continue to remain hydrated and ready in the event the fire activity increases.

Mandatory evacuations and evacuation warnings have been issued in part of Butte County due to the wildfire.

California governor Gavin Newsom on Wednesday proclaimed a state of emergency in Butte County to support the response to the Thompson Fire.

"We are using every available tool to tackle this fire and will continue to work closely with our local and federal partners to support impacted communities," said the governor in a statement, noting that "As we head into some of the most challenging months of wildfire season, the state is better prepared than ever to protect at-risk communities with new tools, technology and resources."

Newsom earlier this week activated the State Operations Center to coordinate the state's response, dispatch mutual aid, and support local communities as they respond to the threats of heat and fire during the early July heat wave.

The City of Oroville declared a local emergency Tuesday evening, and its Fourth of July fireworks celebration show has been cancelled for public safety.

"Due to the ongoing Thompson Fire and extreme fire conditions, local and regional emergency response resources are stretched extremely thin. Consequently, the California Department of State Parks has announced the cancellation of the planned Fourth of July fireworks display," said the city in a news release, adding that with the fire still burning, "emergency response resources must be preserved and dedicated for true emergencies."

Oroville is only about 34 km from Paradise, a Butte County town devastated by the deadly Camp Fire in 2018. A total of 85 people were killed and over 11,000 homes destroyed by the wildfire, the deadliest in the history of California.

Temperatures are set to reach as high as 110 degrees Fahrenheit (43.3 degrees Celsius) in Oroville on Thursday.

About two dozen wildfires are burning in California as high temperatures increase wildfire threat across the western U.S. state.

The U.S. National Weather Service warned on Thursday that "a significant and extremely dangerous heatwave is set to build throughout the West to end this week and into the extended holiday weekend, with several days of record-breaking heat forecast."

High temperatures are forecast to reach into the 105-115 degrees Fahrenheit (40.6-46.1 degrees Celsius) range for interior California away from the immediate coastline, as well as across much of the Desert Southwest, said the service.

Heat impacts can compound over time, therefore it is important to remain weather aware and follow the advice of local officials, the service noted.

  - Xinhua