The investigation into a missing schoolgirl from Bristol, believed to be travelling to Syria, has been handed to the South East Counter Terrorism Unit.
It is hoped the unit's international links will enable Yusra Hussien to be traced.
Avon and Somerset Police say they will continue to work with Yusra's family and the local community in Easton.
The aunt of missing Bristol teenager, Yusra Hussien, says her family is 'broken' and they are 'struggling to come to terms' with her disappearance.
The 15 year old is thought to be in Turkey, trying to make her way to Syria.
Sucdi Al spoke to reporters today about the family's anguish...
The parents of missing 15-year-old Bristol schoolgirl who is believed to be heading to Syria have urged her to come home.Read the full story ›
The family of a missing Bristol school girl have spoke to the media for the first time since their daughter's disappearance.
Speaking at a press conference in Bristol today, Yusra Hussien's mother told reporters she didn't believe her daughter has been 'radicalised' by terrorist websites.
Yusra is believed to have gone to Turkey in a bid to get into Syria.
The family of a missing girl from Bristol believed to be heading to join extremists in Syria are still waiting for news.
The 15-year-old is thought to have met up with a 17-year-old girl from London and headed to Turkey, where they are trying to cross the border into Syria. The teenager vanished from home last week amid fears she's been radicalised.
A spokeswoman for the family of the 15 year old Bristol schoolgirl who is thought to be heading for Syria has said they have 'lost a daughter' and believe she is 'in danger'.
Anira Khokhar addressed a gathering of reporters and cameramen in the girl's home district of Easton.
A neighbour of the missing teenage girl from Bristol who is thought to be heading for Syria says she thought the girl looked sad recently.
"A few days ago I came out of my house and she just came out of her house and I could see that she had a sadness on her face.
"I said 'are you alright?' and she would always answer me with a smile but she just did this [put her hand up]. I was thinking 'what's happened to her?' I didn't know."
Speaking about the suspicions she may have been radicalised and recruited to fight in Syria, she said:
"These people must have really got through to her.
"She always had a smile on her face. I'm shocked this has happened. She is a very good girl. "I'm shocked about her going to fight a war at 15. She still goes to school.
Friends of the Bristol teenager who is believed to be heading for Syria have been talking about their shock at her disappearance.
Pupils outside The City Academy in Easton, Bristol, said the girl had not seemed any different when they last saw her.
"She is a good friend. I have no idea what made her leave.
"I think the police have asked one of her friends to text her to see where she is. She is a really nice girl."
"I was sat next to her and she seemed fine,"
"She didn't have any new friends that we knew about, and she was a completely normal girl."
The Bristol teenager who is believed to be heading to Syria is a student at Bristol's City Academy, it has been confirmed
The British teen who is believed to be travelling to Syria will probably "become a jihadi bride," according to a radicalisation expert.
Haras Rafiq from the counter-extremism think tank, the Quilliam Foundation told Good Morning Britain: "It's more than likely that she will go and become a jihadi bride. She, at the age of 15, will marry someone she considers to be a holy warrior."