A massive wildfire in eastern Arizona continued to burn out of control Wednesday, forcing thousands from their homes and sending a thick blanket of smoke over numerous western states, according to dpa. The Wallow fire, currently the second largest on Arizona record, was ignited 12 days ago by an unattended campfire, and is being fanned by high temperatures and strong winds. It has so far burnt at least 157,000 hectares and remained uncontained Wednesday morning local time. Over 2,000 firefighters are trying to contain the blaze, concentrating their main efforts on saving the rural towns of Eagar and Springerville, where 2,000 people were ordered to evacuate late Tuesday, and 2,000 more placed on evacuation alert. In total an estimated 5,700 people have been forced to flee the flames, filling the area's roads with rag-tag convoys of fully-loaded cars, trailers, caravans and pickup trucks. "We never thought we'd see this roll over the hill, but it's here and we're going to deal with it the best that we can," said Apache County Chief Sheriff's Deputy Brannon Eager. "Some people are frustrated, and I can understand that, and I'm sorry." Working under a sky totally obscured by smoke, firefighters cleared brush on a mountain ridge to build a barrier to protect the towns from the massive blaze. So far only 10 structures have been destroyed and no injuries have been reported. Fire commander Joe Reinarz said Wednesday that a slight lessening of the wind could give firefighters a chance of saving the towns. "Right now, it's not moving as fast. This is our chance. When we get it down here in the pinon and juniper and the grasslands, we can make a lot of advances on getting a corral around this thing," he told reporters. Satellite pictures posted by NASA showed a huge plume of smoke over Arizona, New Mexico and Utah. It affected air quality as far north as Wyoming and as far east as Georgia. Arizona Governor Jan Brewer has declared a state of emergency to deal with the fire, which has so far cost more than 5 million dollars to fight. The worst fire in Arizona history is the Rodeo-Chediski Fire in 2002, in which two fires joined together to burn almost 190,000 hectares.