This undated handout photo obtained February 6, 2015, courtesy of the Mueller family and the office of US Senator John McCain shows 26-year-old Kayla Mueller.(AFP)
The Islamic State claimed Friday that the Jordanian bombings in northern Syria intended to avenge its immolation of a captured pilot had killed an American woman held hostage by the group.
An Islamic State message published by the SITE Intelligence Group, which tracks jihadi activity, said the woman, Kayla Mueller, was killed when the building where she was being held in the Raqqa area collapsed in an airstrike.
"The failed Jordanian aircraft killed an American female hostage," said the message. "No mujahid was injured in the bombardment, and all praise is due to Allah." Mujahid means fighter.
The group said the woman was killed by "fire of the shells dropped on the site."
There was no immediate way to verify the claim by the Islamic State, also known as ISIL. But it identified the hostage by name for the first time and gave her address in Prescott, Arizona, apparently to add credibility to its message. The group also posted photographs of an obliterated house where, it said, Mueller's body had been buried beneath the rubble.
The White House said U.S. intelligence officials were investigating the claim.
"We are obviously deeply concerned by these reports," said Bernadette Meehan, a spokeswoman for the National Security Council. "We have not at this time seen any evidence that corroborates ISIL's claim."
Jordanian officials cast doubt on the Islamic State's claim, calling it propaganda, but they did not explicitly rule it out and confirmed that Jordanian warplanes had carried out airstrikes Friday.
Jordan's foreign minister, Nasser S. Judeh, said on his Twitter account that the claim was "An old and sick trick used by terrorists and despots for decades: claiming that hostages human shields held captive are killed by air raids."
The country's information minister, Mohamad Momani, said in an interview that Jordan was looking into the claim but regarded it skeptically.
"How could they identify Jordanian warplanes from a huge distance in the sky?" he said. "What was the America lady doing in a weapons warehouse?"
The Islamic State, which occupies parts of Syria and Iraq, has executed three other American hostages, all men, in beheadings that it posted on the Internet. A U.S.-led coalition that includes Jordan and other Arab allies of the United States has been bombing Islamic State targets on a frequent basis for months.
Mueller, 26, the only known remaining U.S. hostage held by the Islamic State, is a humanitarian aid worker who disappeared in August 2013 after she had driven into the northern Syria city of Aleppo with her Syrian boyfriend. Her parents received proof of life in May of the following year.
Her family had asked news organizations to avoid identifying her by name while she was still in captivity. But the Islamic State's use of her name and hometown in its message Friday prompted the family to confirm the information, even though there was no proof she had been killed.
In a statement about Mueller, the family called her a passionate aid worker who had been taken captive by the Islamic State after she had left an Aleppo hospital run by Doctors Without Borders, a medical charity.
"The common thread of Kayla's life has been her quiet leadership and strong desire to serve others," the statement said.
Mueller, the statement said, had "devoted her career to helping those in need in countries around the world."
The immolation death of the Jordanian pilot, 1st Lt. Muath al-Kaseasbeh, 26, which was posted on the Internet in a carefully produced Islamic State video on Tuesday, generated new levels of world outrage.
It was never made clear when the pilot, who was captured in late December, had been killed. But Jordanian officials said after the video was released that they believed the militants killed him in early January and had lied that he was alive during negotiations aimed at freeing him.
Jordan hanged two convicted terrorist prisoners, including a woman, in retaliation Wednesday and launched bombing attacks on Islamic State targets in neighboring Syria as a further response for vengeance.
A senior U.S. military official with knowledge of the targets attacked by the Jordanians said the targets in and around Raqqa that were struck were carefully vetted and scrutinized, as with previous strikes, and there were no indications in advance that any hostages were located at the facilities.
"The same high standards we apply to all targets in the vetting stage were applied to these," said the official, who spoke on the condition of anonymity to discuss military operations. "If there's any inkling a person like that was there, we don't go there."
The official cautioned that without proof of the American hostage's death, the statement by the Islamic State could be a ploy to cause the Jordanians and the rest of the U.S.-led coalition to refrain from any heavier airstrikes.
The official said though the Jordanian fighter jets took the lead in the strike in and around Raqqa, they were accompanied by U.S. aircraft, as is standard on bombing runs over territory held by the Islamic State in Syria.
© 2015, The New York Times News Service