The father of a British teenager who was killed fighting in Syria has said his son was "no danger" to the UK.

Abdullah Deghayes (18) and his older brother Amer travelled to Syria without their parents' permission, - Abubaker Deghayes said - adding that they only find out about Abdullah's death through a message on Facebook.

They thought the student was visiting family in Libya. Amer was also wounded in the fighting when he was shot in the stomach.

"I think if somebody has a just cause and he believes in it he should do it" Mr. Deghayes said.

"I think as a Muslim that my son is a martyr"

The student is the nephew of Omar Deghayes, who was held by the United States as an enemy combatant at Guantanamo Bay detention camp between 2002 and 2007 after he was arrested in Pakistan. He was released without charge.

A spokeswoman for the British Foreign Office said "We are aware of the death of a British national and are urgently looking into it".

A spokesman for Sussex Police said: "On Monday, April 14th, we received information that an 18-year-old Brighton man had been killed in Syria in recent weeks. The circumstances of this reported death remain unclear and we are in contact with the family".

The teenager's Facebook page says he was a student at Longhill High School, at Rottingdean, near Brighton. It adds that he intended to be a University of Brighton student from 2015 and works for Adidas.

Messages on Mr Deghaye's Facebook page suggest he left the UK in February. As news of his death in Syria emerged, friends posted tributes on social networking sites.

Finn Langford said "Feels so weird that your actually gone rip Abdullah Deghayes gone but never forgotten sleep tight mate xxx". Harry Hall posted "Never forgett you brother, love ya."

Louise Tierney said "Miss you like mad! Love you mate forever in my heart".