A bomb inscribed with Koranic verses is pictured on a Royal Jordanian Air Force plane at an air base before its launch to strike the Islamic State group in the Syrian city of Raqqa Feb. 5, 2015. ISIS has claimed that the airstrikes killed an American aid worker, but no militants. Reuters

The militant group Islamic State has claimed that the recent Jordanian airstrikes killed an American aid worker it had held hostage. Jihadist threat watchdog site SITE Intelligence Group has identified the hostage as Kayla Jean Mueller on Friday. Her death had not been independently verified.

The U.S. government questioned the claim: "We have not at this time seen any evidence that corroborates" the militants also known as ISIS' statement, said a White House release Friday.

ISIS blamed the alleged death of Mueller, 26, on Wednesday's airstrikes by Jordan aimed at the group’s strongholds in Raqqa, Syria, according to SITE, where the message was translated from an ISIS-affiliated media account. The message, titled “The Failed Jordanian Aircraft Killed an American Female Hostage,” said that Jordanian bombardments outside Raqqa at noon during Friday prayers continued for more than an hour.

There were no American-led coalition strikes in Raqqa during that time, and thus far the lone claim of Mueller's death has come from ISIS. While none of their comrades were injured, the group contended, Mueller was allegedly killed in the process. “Allah made their pursuit disappointed and deterred their cunning, and no mujahid was injured in the bombardment, and all praise is due to Allah,” the message said. It could not be verified whether ISIS’ statements about Mueller were true.

Jordan's interior minister Hussein Majali responded to the claims. "They tried to cause problems internally in Jordan and haven't succeeded," Majali said, according to CNN. "They are now trying to drive a wedge between the coalition with this latest low PR stunt."

The Prescott, Arizona, resident was allegedly captured by ISIS in August 2013, when she disappeared near Aleppo, according to a tweet from New York Times’ foreign correspondent Rukimini Callimachi. A female humanitarian worker was held for $6.6 million ransom last August, according to CBS, and some have thought that worker to be Mueller. The worker was described as having worked for several humanitarian aid groups when she was kidnapped. Mueller gave an interview with Daily Courier in Prescott in May 2013 about having helped reunite a Syrian family, and working with international aid agency Support to Life in Turkey.

Mueller described part of her job there as working with children in refugee camps, drawing, painting and playing with children and helping with counseling sessions. "We give and get joy from playing with these children," she told the Courier. Her involvement in the Middle East began with an interest in the Darfur crisis, and she volunteered for three years with the Save Darfur Coalition, according to the Courier. She was a student at the Northern Arizona University in Flagstaff, and she led several projects on environmental protection.

Jordan vowed retaliation against ISIS when negotiations to exchange the captured Jordanian pilot Muath al-Kaseasbeh for Iraqi terrorist Sajida al-Rishawi fell through, and the pilot was reportedly burned alive. Jordan has said it would beef up its role in the U.S.-led coalition against the extremist group.