BEIRUT: The Islamic State group said a coalition air strike on Friday (Saturday in Manila) killed an American woman it was holding hostage in Syria, in a claim that the United States said it could not confirm. In a statement on jihadist websites, IS said the woman, whom it named as Kayla Jean Mueller, was buried under rubble after a raid by a Jordanian warplane in Raqa. The jihadists said that the plane from the crusader coalition bombed a position outside the city of Raqa after Friday prayers. The family of the 26 year-old aid worker, meanwhile, urged media restraint in their reporting of the IS claim.The IS statement did not show any pictures of a body and there was no independent confirmation of the claim. The United States said it has not yet seen any proof to confirm the IS claim. Mueller was captured in August 2013 in Aleppo after leaving a Medecins Sans Frontieres (Doctors Without Borders) hospital, the family statement said.