Four dead as heatwave grips western US

At least four people have died from the blistering heat that has gripped the western United States and sparked wildfire warnings across the region, authorities have said.

The dead were three hikers and a mountain biker who succumbed to the heatwave in Arizona on Sunday, where record-breaking temperatures were reported in some areas.

Larry Subervi, spokesman for the Phoenix fire department, said one of the victims was an experienced 28-year-old female mountain biker who had embarked on a two-and-a-half-hour ride in the Phoenix area with enough water but got overwhelmed by the heat.

The other victims were a 25-year-old man who died while hiking on the Peralta Trail near Gold Canyon, a 19-year-old woman who died while hiking in the Tuscon area and a man who was found dead near another trail.

"We have a heatwave every year, but we are close to our all-time record in 1990 of 122 degrees Fahrenheit (50 Celsius)," he told AFP.

He said temperatures on Sunday had soared to 120 degrees and the crushing heat was expected to get worse yesterday before easing the rest of the week.

The heatwave has fed wildfires in California, New Mexico and Arizona, forcing evacuations in some areas.

Some 140 families were evacuated in the Santa Barbara area of California where some 2,000 firefighters for several days have been battling the so-called Sherpa fire that has already burned nearly 8,000 acres (3,200 hectares).

In New Mexico, the Dog Head fire about 30 miles (48 kilometers) south of Albuquerque has also damaged two dozen homes and scorched nearly 18,000 acres, forcing evacuations, officials said.

They said that as of last morning, only 9% of the fire had been contained.

Another fire caused by lightning near Cibola National Forest, in New Mexico, has eaten up more than 36,000 acres and was 30% contained.

The fire, which started on May 21, was expected to be contained by late July.