High temperatures and low humidity fueled Colorado's massive wildfire today, putting more residents on alert to evacuate as firefighters struggled to get the blaze under control.
"It's potentially very serious. We're asking all the residents to be on alert and pay attention," fire information officer Mr Joe Colwell said.
Firefighters made progress over the weekend when humidity rose, helping to tame the flames burning about 55 miles southwest of Denver. But the blaze blew up again on Monday, sending about 1,000 residents to safer ground. About 6,000 residents remained evacuated.
Colorado, like other Rocky Mountain states, is in the grip of a severe drought, making timber bone dry and vulnerable to lightning strikes or flying embers from fires left unattended.
Humidity stood at 5 percent, down from around 50 percent over the weekend. Temperatures were expected to be in the 90s and winds could gust up to 30 mph, Colwell said.
The fire consumed more land late on Monday and early on Tuesday, rising to 113,000 acres from 103,000 acres, fire information officer Ron Jablonski said. So far 25 homes have been destroyed, but the figure could be higher, he added.