Los Angeles, Jul 5 (IANS): At least 28,000 people are under evacuation orders as a fast-moving wildfire continued to burn in Northern California amid a 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 evening, with only 7 per cent containment, Xinhua news agency reported.

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 to increase 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.