The Los Alamos laboratories were temporarily closed last week when the forest fires moved dangerously close to stored plutonium and high explosive.
Kathy Delucas, a spokeswoman for the Los Alamos Nuclear Laboratory, said the fire had gutted the historic buildings of the Manhattan Project, in which atomic bombs were developed and manufactured during the World War II.
Two of the bombs - known as Fat Man and Little Boy - were dropped on the Japanese cities of Hiroshima and Nagasaki in August 1945, killing tens of thousands of people.
The Los Alamos laboratories were temporarily closed last week when the forest fires moved dangerously close to stored plutonium and high explosive.
However, officials from the laboratory have insisted there is no threat to the stockpiles, which are stored underground.
"No permanent structures, scientific facilities, or facilities that handle radioactive or hazardous materials have been burned", said Ms Delucas.
The US Department of Energy air monitors, which have been in the area since Thursday, have detected only normal radiation levels, officials said.
Out of control
US forestry officials say the forest fires may continue to burn out of control for weeks.
"With the fire burning in all directions, it will be a long time before it can be contained," said Jim Paxon, a spokesman for the US Forest Service.
Click here to the area under threat
The blaze in New Mexico flared up after officials from the National Park Service embarked on what was supposed to be a controlled burn to remove undergrowth.
According to the latest figures, the fires have scorched about 17,000 hectares (42,000
acres) as some 1,400 firefighters struggled to contain them.
"We simply don't have enough men (to fight the blaze)," Paxon said.
It has destroyed more than 260 homes in the town of Los Alamos alone.
About 25,000 people have been evacuated from Los Alamos, as well as residents of the towns of White Rock and Espanola.
No injuries have been reported from the blaze,
Grand Canyon
Meanwhile, extra firefighting resources and calmer winds have helped to prevent another wildfire from spreading in the Grand Canyon National Park, in Arizona.
The size of the fire there, which has already destroyed 7,000 acres (2,800 hectares) of forest, has not increased since Friday, when the winds allowed rescue teams to fight the blaze.
The Grand Canyon fire was also started deliberately, but quickly spread out of control.
Click here to return
The US inferno
42,000 acres of forest destroyed in New Mexico
7,000 acres of the Grand Canyon National Park burned
Historic Manhattan Project buildings destroyed
25,000 people evacuated in New Mexico
261 houses razed
Damage from the fire is estimated at more than $1bn.
Related to this story:
Fires spread in US
(13 May 00 | Americas)
In pictures: Evacuation of Los Alamos
(11 May 00 | Americas)
Forest fire shuts nuclear lab
(09 May 00 | Americas)
Los Alamos evacuated
(11 May 00 | Americas)
Internet links:
Los Alamos Fire Department |
Bandelier National Monument |
Los Alamos National Laboratory |
US Department of Energy |
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