At least 19 elite firefighters have been killed in the US state of Arizona, while battling a fierce wildfire. Much of the western US has experienced record temperatures in recent days.
According to authorities, the firefighters died on Sunday afternoon while fighting the Yarnell Hill wildfire, north of the city of Phoenix. The Arizona State Forestry Division had earlier declared 19 firefighters missing but it has not been confirmed whether the dead were these same firefighters.
A local fire chief from the city of Prescott, Arizona, said the dead were specially-trained "hotshot" firefighters who had been forced to deploy to their fire shelters after being caught up in the blaze, which has forced evacuations of at least 50 homes.
The fire shelters are tent-like structures meant to shield from flames and heat.
"The entire hotshot crew had been killed by the fire," said Prescott fire chief Dan Fraijo.
The fire broke out on Friday, and has covered 800-1000 acres, according to forestry officials. News site the Arizona Republic reported the fire had still not been contained by Sunday night, local time.
The western United States has been suffering under a heatwave in recent days. According to the Los Angeles Times, the Death Valley in eastern California recorded a temperature of 54 degrees (129 Fahrenheit), the hottest ever in the US.
Firefighters were 'heroes,' says Obama
The deaths are believed to have been the deadliest firefighter fatalities in 80 years, since 29 firefighters were killed in Griffith Park in Los Angeles in 1933.
The US president Barack Obama has paid tribute to those killed on Sunday, and promised assistance from the federal government.
"They were heroes - highly-skilled professionals who, like so many across our country do every day, selflessly put themselves in harm's way to protect the lives and property of fellow citizens they would never meet," Obama said, as he headed to Tanzania on the final leg of an official African tour.
"The federal government is already assisting, and we will remain in close contact with state and local officials to provide the support they need."
"But today, Michelle and I join all Americans in sending our thoughts and prayers to the families of these brave firefighters and all whose lives have been upended by this terrible tragedy."
jr/ccp (AP, AFP, dpa)