With tears streaming down her face primary school dinner lady Safiya Hussien, 40, said her missing 15-year-old daughter Yusra's decision to leave the country had 'torn' her heart in two.
The teenager vanished from school in Bristol a week ago and boarded a flight to Turkey from Heathrow Airport with a 17-year-old girl from London.
Police fear the duo have been radicalised and are heading for the Syrian border to join terror network IS.
In an emotional TV appeal her mum begged Yusra: "Please come back. Please, we miss you. Please.
"I'm your mum. I love you 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."
Safiya and her youth worker husband Mohamed (corr), 41, said with every passing day there were growing `more and more concerned about her safety and welfare' and 'struggling to come to terms with this situation'.
The `bright bubbly' youngster was a `typical teenager' who played table tennis, rode her bike and loved running.
They had no inclination she was planning to leave the country and no `concrete evidence' she was joining IS.
But the `pain that we as parents feel at not knowing her safety is very distressing' and `something we believe every parent can relate to'.
Mohamed told his daughter: "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.
"Anyone who can assist the police with any inquiries could you please do so immediately.''
Family friends described Yusra as an aspiring dentist and grade A student who was devoted to her education.
But they said she had recently become tied to her mobile phone and computer after apparently viewing extremist material in chat rooms and online forums.
Local Labour councillor Afzal Shah said it appeared she had `self-radicalised'.
Yusra, who is of Somali descent, left for school at the City Academy, Bristol, as usual on the morning she vanished but was not there when her dad went to collect her that afternoon.
Officers are investigating how the two girls were allowed to travel to Turkey without adults.
Police said their tickets had been bought in advance.
Mr Shah said detectives believe Yusra may be in the east of Turkey near the Syrian border.
He added: "IS is a menace to the whole of society and have nothing to do with the Muslim faith. They're violent and extortionist thugs. It's absolutely tragic. The family had no clue.''
The councillor called for further measures to be enforced to ban children from travelling abroad apart from with parental consent or in exceptional circumstances.
"My understanding is that the Border Agency staff have discretion or in fact the airlines have discretion,'' he said.
"Well I think that discretion needs to be taken away from them.''
The South East Counter Terrorism unit was last night 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."
