The parents of missing 15-year-old schoolgirl Yusra Hussien, who is believed to be heading to Syria after becoming radicalised, have urged her to come home.

The teenager's parents, Mohammed and Safiya, said they were becoming increasingly concerned for her.

"We are making this heart-breaking appeal for our daughter, Yusra Hussien, who has been missing since Wednesday September 24," they told reporters at a police press conference in Bristol.

"As every day passes we become more and more concerned about her safety and welfare."

Mr and Mrs Hussien said: "Yusra, our daughter, is a very young bright bubbly girl who is loved by not only her family but her peers, teachers and her community.

"She's a typical teenager - she loves to play table tennis and to ride her bicycle and she used to run with her brother, who's the next Usain Bolt.

"Our family is very heartbroken and we are struggling to come to terms with this situation.

"The pain that we as parents feel, at not knowing her safety, is very distressing, and is something we believe every parent can relate to.

"There have been many assumptions and speculations claiming that Yusra is travelling to Syria, that she may be an extremist, or that she is planning to become a jihadist bride, all of which have not, as yet, been proved with any concrete evidence.

"We would like to make a request to the media to not state anything which is both incorrect and not backed by evidence."

Mr and Mrs Hussien added: "Yusra we are missing you, if you are watching this please contact us, you are not in trouble and we are not angry with you. We just want you back home with us."

Mrs Hussien appealed directly to her daughter: "From your mother - please dear Yusra, I love and I miss you, my heart is torn, and I want you home as soon as possible.

"Your brothers and baby sister are missing you and the house has not been the same since you left."

Mr Hussien said: "From your father - Yusra, I'm not angry, I just want you to be safe. Please come back.

"We are working with the police to find you and we are praying to god that we will find you safe and bring you back home.

"We would just like to thank the Somali community and all the other communities that have shown us their support and love. We also want to give our gratitude to the police for their ongoing support.

"Anyone who can assist the police with any inquiries, could you please do so immediately."

Yusra, from the Easton area of Bristol, is thought to have met up with a 17-year-old girl from London and headed to Turkey, where they are believed to be trying to cross the border into the neighbouring war-torn state.

It is unclear how the teenagers met, but they vanished from their homes last week amid fears they have been radicalised.

Family friends of Yusra described her as an aspiring dentist and grade A* student who was devoted to her education.

However, they said the girl had recently become tied to her mobile phone and computer after apparently viewing extremist material on chat rooms and forums online.

Afzal Shah, Labour councillor for Easton ward, said it appeared Yusra had "self-radicalised" rather than having been exposed to such material through local institutions.

"The understanding that I have is that it was self-radicalisation as opposed to having anything to do with any institutions," Mr Shah said yesterday.

"There may possibly be other individuals involved but that's something the police are looking into. There are so many forums and chat rooms on the internet, it is very easy to get led astray.

"We don't know how she got to that stage, I don't know how long it has been going on for but certainly not long from speaking to the family.

"This is a young girl, she was an A* student, nobody had any indication of it whatsoever. She was very focused in her studies.

"Even when she would go to any reading circles she would be accompanied by a family member. She is a very intelligent individual.

"Her family are loving individuals who always put their children first. They are completely shocked."

Yusra, who is of Somali descent, left for school at the City Academy, Bristol, as usual on the morning of her disappearance but was not there when her father went to collect her that afternoon.

Officers are investigating whether the two girls travelled together from Heathrow Airport to Istanbul, Turkey, on their way to Syria.

The girls' disappearance follows that of twins Zahra and Salma Halane, 16, from Manchester, who are thought to have travelled to Syria in July.

British authorities have expressed increasing concerns about hundreds of UK-born would-be jihadis who have gone to join Islamist forces in the Middle Eastern state.

Home Secretary Theresa May has already removed the passports of 25 Britons attempting to reach there, while 103 people have been arrested in relation to terrorism in Syria. Of those arrested, 24 have been charged and five convicted.

But Mr Shah called for further measures to be enforced to ban children from travelling abroad, apart from with parental consent or in exceptional circumstances.

He said police and Yusra's family are examining how she came to board a flight to Turkey and it is not yet known how that was funded.

"But this also begs the question, how could a 15-year-old child be allowed to board a plane, just like that?" he asked.

"My understanding is that the Border Agency staff have discretion or in fact the airlines have discretion. Well I think that discretion needs to be taken away from them.

"We need a lot clearer guidance from the Government and I would call on Theresa May to actually bring that within the new guidelines - to say that children, unless expressly given permission or unless there are exceptional circumstances, should not be able to board on their own."

Mrs Hussien wept as she issued a direct plea to her daughter at the packed press conference in Bristol.

"Yusra, I am your mum, I love you," she said. "Please, please, please, we miss you, come back.

"I love you so much. All your brothers and your sister miss you so, so much.

"The house is not the same when you left. Please, please - look at me."

Mrs Hussien was supported by Yusra's aunts, Sucdi Ali and Ikram Mohamed, who also read parts of a prepared statement to media.

The family said they did not wish to comment on extremism or speculation the teenager had become radicalised online.

Speaking at the conference, Chief Superintendent Jon Reilly, Bristol's district commander, said the force would not be commenting on the investigation.

"The investigation's priority remains finding Yusra and bringing her back to the UK as soon as we can," he said.

Officers from the South East Counter Terrorism unit are now leading the search for the two girls.

A spokesman said: "Officers are providing support to both families and are working to identify where they are and encourage them to return home safely.

"Travelling to Syria is extremely dangerous and anyone who is considering travelling to the region is putting themselves at great risk.

"We urge anyone who is concerned about someone planning on travelling to Syria to contact police and get access to the support available. Our aim is to not criminalise young people, it is to prevent tragedies."

mfl