The parents of a privately educated young woman from Glasgow who is supporting the Islamic State in Syria have accused her of betraying them as they pleaded for her return.

The family of Aqsa Mahmood, 20, from Pollokshields, Glasgow, spoke out as a desperate hunt was under way to save the life of a Scottish-educated hostage whose life is under threat from ISIS terrorists.

The man, who is not being named by The Herald out of respect for the wishes of his family and the Foreign Office, has been threatened by the same man who killed US journalists Steven Sotloff and James Foley. "Every possible option" is being considered by the UK Government to save him and other hostages, including air strikes.

Prime Minister David Cameron said: "We have faced down threats like this before and will do again."

Ms Mahmood's parents Khalida and Muzaffar spoke out after their daughter appeared to have made comments on social media calling for a repeat of the murder of soldier Lee Rigby. She has married a militant fighter.

The couple said: "We still love you, Aqsa, but we now have to put your family, your brother and sisters first as you have betrayed us, our community and the people of Scotland. You have torn the heart out of our family and changed our lives forever. Please come home."

First Minister Alex Salmond added: "One person being drawn into that circle of evil is one too many so we're very concerned about it."