Family of US Islamic State hostage hopeful she is still alive

The parents of an American humanitarian worker held hostage by the Islamic State group since August 2013 said on Friday they are still hopeful she is alive, after the group said she was killed in a bombing by Jordanian fighter jets.

In a statement released by a family representative, Carl and Marsha Mueller of Arizona, parents of Kayla Jean Mueller, asked the Islamic State group to contact the family privately.

"You told us that you treated Kayla as your guest, as your guest her safety and well-being remains your responsibility," they said in a message directed to "those in positions of responsibility for holding Kayla."