A rapidly-growing fire south of Lytton, B.C. has forced the evacuation of 16 homes.

About 20 others are under an evacuation alert, meaning they may need to leave at any time.

The evacuation order applies to all properties on the east side of South Spencer Road from 3800 South Spencer Road north to the boundary of the Papyum 27 Indian Reserve, said a news release issued Wednesday night from the Thompson-Nicola Regional District.

Fire information officer Kelsey Winter says the fire burning near the Lytton First Nation is aggressive and fuelled by wind.

The B.C. Wildfire Service says the fire is about 400 hectares in size and is moving at a moderately vigorous speed.

"We are seeing quite aggressive fire behavior," said Winter.

"The winds in the valley are quite strong, and we've seen quite a few trees get involved in terms of candling and quite a big push just in the valley there," she said.

Air tankers, two helicopters and 56 firefighters are battling the fire.

There is no word what caused it, and no road closures are currently in effect.

"At this point we have the necessary resources dedicated to this fire," Winter said.

"So we're making sure we halt the spread as fast as we can, and really keep as many crews on the ground working on containment at this time."

The wildfire service says the fire is moving up slope, away from homes.

With files from Canadian Press