RESERVE, New Mexico - Crews who've been battling a massive wildfire in eastern Arizona for two weeks shifted their focus Monday to New Mexico, where they lit fires to stop its advance and protect another mountain town in its path.

Smoke from the Wallow Wildfire obscures the sun at a road check point west of the Reserve, New Mexico June 13, 2011. [Photo/Agencies]

In the opposite corner of New Mexico, near the Colorado border, winds kicked up flames at a wildfire that had already forced evacuations and closed 20 miles (32 kilometers) of the main north-south highway through both states.

"We're watching trees explode before our eyes. It's horrendous," said Barbara Riley, a schoolteacher and bed-and-breakfast owner in Raton, in northeastern New Mexico.

The eastern Arizona fire has been burning since May 30; efforts to stop its spread finally met with success over the weekend as high winds caused no major growth.

Residents of two Arizona towns on the fire's northern edge were allowed to go back home Sunday, and thousands streamed into Eagar and Springerville through the day. Crews have stopped its northern advance and are now trying to corral its eastern advance into New Mexico by burning a line in front of the fire that it can't cross.

In Luna, New Mexico, about 5 miles (8 kilometers) from the Arizona line, crews lit fires to keep the flames from getting into town, Catron County Undersheriff Ian Fletcher said Monday. The operation began Sunday night, and the 200 or so residents did not have to leave. Fletcher said an evacuation plan is in place in case the situation changes.

"It's holding, and they're pretty confident this morning," Fletcher told The Associated Press. "These guys are getting after it. It's kinda neat to see. I was concerned earlier, but they seem to have it wrapped up pretty well, or it's going well for them right now."

The eastern Arizona fire had grown to 706 square miles (1,830 square kilometers) by Monday morning, and was just 10 percent contained. But firefighters have been sounding increasingly confident at their daily briefings that their efforts were paying off.

Meanwhile, fire crews are attacking a wildfire burning on about 1,800 acres (728 hectares) in southern Colorado in dry, windy conditions. Gusts of up to 45 mph (72 kph) and dry weather Monday helped drive the fire northwest of Westcliffe in the San Isabel National Forest.