American female hostage ISIS
ISIS claimed that American aid worker Kayla Mueller was killed in a Jordanian airstrike in Raqqa.Twitter

Government officials and experts are doubting the Islamic State's claims that an American woman it had held hostage was killed in a Jordanian airstrike in Raqqa on Friday, given that it produced no video or photos to back up its claim. 

ISIS claimed that 26-year-old American aid worker Kayla Jean Mueller, who was abducted in August 2013, was killed when an air strike targeted a building she was being kept in, in Raqqa. 

The Islamic State shared a report through its Twitter accounts on Friday, declaring Mueller's death, showing photos of a destroyed building. 

The report, translated to English by SITE Intelligence, an online jihadist watchdog, reads:

"The Failed Jordanian Aircraft Killed an American Female Hostage. The criminal Crusader coalition aircraft bombarded a site outside the city of ar-Raqqah today at noon while the people were performing the Friday prayer. The air assaults were continuous on the same location for more than an hour. Allah made their pursuit disappointed and deterred their cunning, and no mujahid was injured in the bombardment, and all praise is due to Allah.

It was confirmed to us the killing of an American female hostage by fire of the shells dropped on the site, and she is Kayla Jean Mueller."

However, the US military has reportedly said that no airstrikes were conducted in Raqqa by coalition forces on Friday. 

The Jordanian government also expressed doubt that the American was killed in an airstrike by Jordan, calling it a 'trick'.  

"An old and sick trick used by terrorists and despots for decades: claiming that hostages human shields held captive are killed by air raids," Jordanian Foreign Minister Nasser Judeh tweeted on Friday.

National Security Council spokeswoman Bernadette Meehan said the White House is "deeply concerned" by the reports but added that there was no evidence to support the claims.

Foreign policy experts, too, have not bought into ISIS' claim yet. 

"Of course we should be skeptical, it's far too pat," Daveed Gartenstein-Ross, a senior fellow from national security think tank Foundation for Defense of Democracies told NBC News