Evacuations are under way around Summerland, B.C., after a new wildfire near Okanagan Lake exploded in size.

Erick Thompson with the Regional District of Okanagan-Similkameen’s emergency operations centre says the fire was first detected at 5:30 p.m. Friday, but it has grown to 50 square kilometres in about three hours.

He says the fire poses an immediate threat and those in the evacuation zone from Summerland north to Peachland need to get out in the face of one of the “quickest-moving, fastest-growing” fires the area has ever seen.

Thompson says in a video briefing that the fire is showing aggressive rank-five behaviour, meaning that it has a fast-moving flame front with “long-range spotting” that potentially starts new fires.

The regional district says residents should evacuate immediately if they are threatened by the Bald Range fire, which poses a “significant risk to life.”

The evacuations come about a week after the Bradley Creek fire to the north destroyed about 230 homes on the Okanagan Indian Band reserve and forced thousands to flee.