A TERROR investigation has been launched after two young British girls travelled to Syria, police say.
Salma and Zahra Halane, who used to live in Bolton but have since moved to Chorlton, Manchester, disappeared from their parents' home on June 26.
Now police say they believe the girls have travelled to Syria, and anti-terror cops are investigating why and whether they were helped.
The twins, who have 28 GCSEs between them, are believed to have travelled first to Turkey before crossing the border into Syria.
The Muslim youngsters, said to be "deeply religious", have ignored their family's pleas for them to come home and told them they have no intention of returning.
It is understood an older brother from the large Somalian family 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 travelled to join him.
Det Ch Supt Tony Mole, who is in charge of the police's north west counter-terrorism unit, said: "First, I want to stress that the welfare of these two teenagers is our overarching priority.
"Two 16-year-old girls left the UK on June 26 and we believe that they have since entered Syria.
"Since this story broke in the media at the weekend there has been a lot of speculation about why the girls left the country.
"At this stage we don't know for sure why they are there or exactly who they are with.
"As this is now developing into an investigation, the north west counter terrorism unit is leading on this inquiry.
"This investigation now has two main strands - to safeguard the girls wherever possible and to assess any further lines of enquiry as the investigation progresses.
"They are clearly posing a threat to themselves, and potentially the community, and their family and friends are concerned for their well-being."
He added that police are running a national programme to prevent people being radicalised or influenced into travelling to "a volatile and dangerous region".
Anyone with information can call the anti-terrorist hotline on 0800 789321.