Firefighters in British Columbia struggled Sunday morning to contain some 500 forest fires that have forced the evacuation of 2,700 people and left 2,300 more ready to leave at a moment's notice.

Winds and a lack of humidity helped revive two blazes that have been burning for nearly two weeks at Terrace Mountain, near the town of Kelowna, about 400 kilometers (249 miles) east of Vancouver.

The fires, which were estimated on Saturday to be affecting around 4,575 hectares (11,305 acres), grew significantly overnight, firefighter spokeswoman Suzanne Von der Porter told the Vancouver Sun newspaper.

The danger posed by the rapid progress of the blazes forced firefighters to pause their efforts temporarily, she said, adding that 2,700 residents who had returned to their homes two days earlier were ordered to evacuate them again on Saturday.

Another 2,300 residents of the town of Lillooet have been told to be ready to evacuate at a moment's notice, according to local media, after a fire sparked by lightning continued to rage close by on Sunday morning.

"The situation is critical. It's still hot and dry. We did get a few drops of rain, but nothing significant for this fire," said Isabelle Jacques, a fire information officer with the province's Forest Service.

Temperatures that have consistently hit over 30 degrees Celsius (86 degrees Fahrenheit), combined with low humidity and lightning, have caused the worst forest fires in British Columbia's history.

More than 1,000 firefighters from the province have been deployed, along with 400 of their colleagues from Ontario, Manitoba, Saskatchewan and Alberta. Another 250 firefighters joined the efforts on Sunday.

British Columbia's Premier Gordon Campbell said Friday that 531 fires were burning across the province and he warned residents to avoid local forests, where they could be trapped by fires or accidentally start new ones.