No new homes were destroyed for a second day running on Tuesday and a fire line at a highway has been holding firm, an official told Reuters news agency.

But lightning strikes are forecast for Wednesday, which could still reverse the fire-fighters' gains, and no rains are expected.

President George W Bush, who spent Tuesday visiting evacuees from Show Low, has declared the area a disaster zone.

"Mother Nature is still in control," fire official Jim Paxon said as a blaze the size of Los Angeles continued to burn out of control.

Arizona burning

Now covers 152,000 hectares (375,000 acres) More than 30,000 evacuees Some 400 homes burnt down

Flames are less than 0.8 kilometres (0.5 miles) from the edge of Show Low, a town of 7,700 people which is now largely deserted.

Mr Paxon said that if favourable weather conditions held through Wednesday there was a good chance of gaining some ground on the fire, which is the largest in Arizona's history and one of the biggest on record in the American West.

Battle for Show Low

Some 2,000 fire-fighters are battling the blaze, which grew when two separate fires merged on Sunday, both suspected of being started by humans.

	:	US Fires
In pictures: Fighting the wildfires

On the western edge of Show Low, bulldozers dug a trench 27 metres (90 feet) wide and crews set fires in a bid to burn their way back into the main blaze, cutting it off from new fuel.

In the town itself, fire-fighters cut down trees close to homes, removed firewood and moved propane tanks away.

Have you been affected by the wildfires? E-mail us with your experiences.

It looked like a scene from Dante's inferno

Phil Briers, Arizona

As sprinklers water down houses close to the fire line to prevent stray embers from igniting, helicopters have been dumping thousands of gallons of water and retardant on the flames.

Phoenix Fire Captain John Brunacini said crews were keeping calm but working flat out: "We're like ducks on water - calm on top but our feet are going underneath."

Drier forests, higher temperatures and a lack of winter precipitation have made the conditions ideal for this fire to spread.

In addition, according to US Forest Service official Dorman McGann, pine forests have became choked with underbrush since environmentalists blocked efforts to clear it.

Nine states

Fires are also burning in eight other US states, at an estimated cost of $10 million a day to the federal government.

The stakes are high in Show Low, named after a historic local card game

While President Bush has announced $20m in relief for Arizona, other states such as Colorado face fires on a similar scale.

There are now 20 fires burning across the nine states, with more than 1m hectares (2.5 million acres) of land burnt to date - more than double the annual 10-year average.

In Colorado, fire-fighters are up against hot weather and shifting wind near Durango, where a fire has burned nearly 26,800 hectares (67,000 acres) and at least 45 homes.

South-west of Denver, crews are bringing a fire under control after it charred 54,800 hectares (137,000 acres) and destroyed at least 133 homes.