VANCOUVER -- A wildfire that prompted an evacuation order for more than 300 properties in B.C.'s Okanagan has grown to about 250 hectares in size.

The latest estimate is about 25 times bigger than the B.C. Wildfire Service initially reported late Tuesday afternoon, when the blaze was first discovered on the east side of Skaha Lake.

"We anticipate we will see further growth once we are able to get a more accurate tracking of the fire," the service wrote on Twitter.

The fire is burning about six kilometres north of Okanagan Falls, forcing the Regional District of Okanagan-Similkameen to issue an evacuation order for 319 properties in the Heritage Hills area.

The B.C. Wildfire Service said ground crews are battling the blaze with support from air tankers. They described the fire as a "rapidly evolving situation."

A full list of the properties under evacuation order is available here.