A young woman from Glasgow has travelled to Syria and has been promoting terrorism back home via her Twitter account, it is understood.
Aqsa Mahmood, 20, was reported missing by her family in November 2013.
A Twitter account under the name Umm Layth, believed to be Ms Mahmood, said: “Follow the examples of your brothers from Woolwich, Texas and Boston.
“If you cannot make it to the battlefield then bring the battlefield to yourself.”
The post was made on the Twitter account in June. The account has now been deactivated.
Ms Mahmood was a pupil at Craigholme School and Shawlands Academy in Glasgow.
A Police Scotland spokesman said: “A (then aged) 19-year-old female from Scotland was reported missing to Police Scotland by her family in November 2013.
“Inquiries are ongoing in relation to her whereabouts and we are supporting her family.”