Twin teenage girls who are thought to have travelled to Syria are "deeply religious Muslims", police understand.
It is understood an older brother has joined the extremist militant group Islamic State of Iraq and the Levant (Isis), and one line of inquiry is that the girls may have flown out to join him.
The girls, from a large Somalian family, flew from Manchester International Airport to Turkey which borders Syria where the civil war involving Muslim militants is raging.
Greater Manchester Police said the pair had been in contact with relatives since their departure.
More top news
Ranvir Singh returns to Calais a year after first reporting from there for Tonight on the plight of migrants seeking a way into Britain.
Sir Bruce Forsyth talks to ITV News about his encounters with the Queen and his years in the spotlight throughout her reign.
A seven-year-old girl was shot in the head at her home by her estranged father, before he turned the gun on himself, an inquest has heard.