A growing wildfire in eastern Washington state has caused two medical facilities to shelter in place and some residents have been asked to evacuate.

The fire, known as the Gray Fire, has burned through 500 acres near Medical Lake, Washington, Spokane County Fire District 10 said in a social media post on Friday.

Evacuation orders have been placed for residents living in Medical Lake and the area south of the city, according to the county fire district.

The fire was initially reported in the neighborhood of Lakeland Village, southwest of Medical Lake Friday afternoon, the county fire district said.

Authorities have activated aircraft to respond to the fire, the fire district noted.

Two nearby state-operated medical facilities, Eastern State Hospital and Lakeland Village Residential Habilitation Center, are currently sheltering in place, Norah West, assistant director of the Washington State Department of Social and Health Services, told CNN.

"This is an emerging situation and we are working to confirm details on the ground," West added.

No casualties have been reported, Spokane County Fire District 10 spokesperson Sarah Jydstrup told CNN.

Medical Lake is about 15 miles southwest of Spokane.