A wildfire raging in the South Okanagan has prompted air quality and evacuation alerts.

The Richter Mountain fire, blazing near the Crowsnest Highway between Osoyoos and Keremeos, has grown to 400 hectares – five times larger than it was reported to be on Friday. 

BC Wildfire Service says strong winds that were helping to keep the fire in check have shifted, which has made fighting the blaze a challenge for the 100 firefighters on the ground and nine helicopters in the air. 

"Helicopters continue bucketing water to cool hot spots and slow fire spread," the wildfire service said on Twitter. "Drivers should proceed through the area slowly without stopping and watch for falling rocks and debris along the highway."

On Friday, an evacuation alert was put in place for 10 properties in the Cawston area and on Sunday, crews said the evacuation alert was still in place. 

Highway 3, also known as the Crowsnest Highway, was closed for several hours Friday morning as the fire got close to the road. 

A local air quality alert has also been issued for smoky skies in the area.