Firefighters are working to gain control of a blaze that’s threatening homes south of Penticton, B.C.

The fire, which was initially reported Tuesday afternoon, is burning on a hillside in the area of Ponderosa Point, in the 1,200-person community of Kaleden located in the South Okanagan.

Castanet reported that the fire was burning quickly uphill, and that residents had been asked to evacuate. Flames tore through at least one home and an outbuilding "that we know of," the fire chief told Castanet.

He said a firefighter was injured, but was treated by the BC Ambulance Service and has since returned to duty. It has not yet been confirmed whether anyone else is injured.

The chief, Denis Gaudry, said the blaze was first reported as a single tree on fire, at around 3:45 p.m., but that the flames quickly spread with help from the wind.

He said the fire was "absolutely not" contained and that he expects more homes to be evacuated through the night.

A fire official said that at least 100 properties had been evacuated by Tuesday evening, and that residents were being taken to Penticton. The official said the fire was most likely human caused, because there had not been any lightning in the area at the time.

FortisBC said about 170 homes were without power as of 7:30 p.m., and that crews were working to restore it while heeding the directions of fire officials.

The BC Wildfire Service confirmed that it was called in to help the Kaleden Fire Department, but was unable to provide much more information on the damage caused.

The service told CTV News that there were about 35 firefighters on the ground, and that the fire was about one hectare in size. Later reports suggested the fire had grown to 5.5 hectares by 7 p.m.

There are two helicopters and three fixed-wing aircraft at the scene, Castanet reported. The Penticton Fire Department is also sending support.

A command centre has been set up at the fire hall for those in need of emergency services. Evacuees have been asked to register at the community centre on Power Street, and anyone impacted can call 205-809-6561 for directions to a reception centre set up by the Regional District of Okanagan-Similkameen.

Smoke could be seen across the lake as firefighters fought the flames, witness Shane Dehart told CTV News.

"Different coloured smoke, and a lot of smoke. And it seems to be where the one helicopter is attacking it from the north. He seems to be focusing right on a couple of homes right above Ponderosa Point.”

Marla Truman, who lives about 10 kilometres away in Okanagan Falls, said she could see the smoke from work in Penticton around 4:30 p.m. In the hours since then, she said she saw water bombers and firefighters working from the ground.

She said the area of the fire is "very habitated," and that the wind was blowing flames towards the town.

"I did hear – nothing official – but I know they were evacuating some people as well that are in the area, so it's definitely a bit of a dicey situation at the moment," Truman said.

She said fires are common in the region during the summer months: "It's really just a matter of when and where."

Truman's husband was at the Okanagan Falls fire station on standby, ready to head to Kaleden if needed.

With files from CTV Vancouver's Sarah MacDonald, Sheila Scott, Carly Yoshida-Butryn and Scott Hurst