LOS ANGELES, July 22 -- A fast-growing wildfire in Southern California, western U.S. state of California, has destroyed three homes and damaged four others in Riverside County, authorities said on Monday.

The wildfire, dubbed the Hawarden Fire, was first reported at 1:05 p.m. Sunday local time in the Hawarden area. As of Monday morning, the blaze had burned a total of 527 acres (2.13 square km), according to the City of Riverside Fire Department.

There are 1,500 residences in the surrounding area and the Riverside Police Department is helping evacuations, Riverside Fire Department Deputy Chief Steve McKinster said at a Monday morning news conference.

One firefighter suffered a minor injury. Twenty-one engines and two hand crews are fighting the fire, he added.

There has been no forward progress of the fire, and it is fully contained within the established perimeter. Additional hot spots are being closely monitored throughout the day, said the department in a Facebook post, adding that the City of Riverside Arson Task Force is investigating various reports of fireworks to determine the cause and origin of the fire.

Another large wildfire in the area, the Eagle Fire, broke out Sunday afternoon and also triggered evacuations. The fire has burned over 1,600 acres (6.47 square km) with 50 percent containment as of Monday morning.

An air quality alert was issued by the South Coast Air Quality Management District to residents in areas impacted by smoke. The agency said smoke from the Eagle Fire and Hawarden Fire will cause elevated PM2.5 levels in parts of the Riverside County, and the Air Quality Index may reach unhealthy for sensitive groups or higher in areas impacted by smoke.

  - Xinhua