The Islamic State (ISIS) group claimed on Friday that a female American hostage had been killed in an air strike in Syria by the U.S.-led coalition, AFP reported.

In a statement on jihadist websites, ISIS said the woman, whom it named as Kayla Jean Mueller, was buried under rubble after a raid by a Jordanian warplane in Raqa.

“The plane from the crusader coalition bombed a position outside the city of Raqa after Friday prayers,” it said.

“No fighter was wounded but we can confirm that an American hostage was killed in the strikes.”

The statement did not show any pictures of a body and there was no independent confirmation of the claim. American officials declined to comment.

“I cannot confirm those reports in any way. I’m not going into specifics of Americans held overseas,” State Department deputy spokeswoman Marie Harf said, according to AFP.

National Security Council spokeswoman Bernadette Meehan later said the United States has not yet seen any proof to confirm the claim.

“We are obviously deeply concerned by these reports. We have not at this time seen any evidence that corroborates ISIL’s claim,” she said.

The Britain-based monitor the Syrian Observatory for Human Rights said more than 30 ISIS jihadists were killed in coalition raids Friday on the Raqa area.

It said they died in raids on “positions and depots sheltering military vehicles and tanks, east and west of the city of Raqa”.

IS has seized swathes of territory in Iraq and Syria, ruling with a brutal version of Islamic law.

It has murdered both locals and foreigners, including two American journalists, an American aid worker, two British aid workers, two Japanese hostages and a Jordanian fighter pilot.

Jordan, one of several Arab countries in the U.S.-led coalition, vowed a harsh response after ISIS released a video this week showing the burning alive of the pilot, Maaz al-Kassasbeh.

Kassasbeh was captured in December after his F-16 crashed in Syria while on a mission against the Sunni extremists.

(Arutz Sheva’s North American desk is keeping you updated until the start of Shabbat in New York. The time posted automatically on all Arutz Sheva articles, however, is Israeli time.)