A teenager who ran away from Britain as a 15-year-old schoolgirl to join the Islamic State group now wants to return home.
Heavily pregnant with her third child, Shamima Begum, now 19, was tracked down by The Times newspaper to a refugee camp in northern Syria.
She fled her home in east London with two other schoolgirls in 2015.
Here are some key questions her case raises:
1. What action might she face if she is allowed to return to the UK?
Home Office Minister Ben Wallace has said everyone who returns from taking part in the conflict in Syria or Iraq must expect to be investigated by the police.
This will determine if they have committed criminal offences, and to ensure that they do not pose a threat to national security.
Wallace said on Thursday: “The message is, to all people out there, which is if you have been out there, against the advice of the foreign office to go and engaged in support or activities of terrorism you should be prepared, if you come back, to be questioned, investigated and potentially prosecuted for terrorism offences.”
Wallace added: “Some who went out [to Syria] as amateurs are now professional terrorists.”
While the prime minister’s spokesperson said: “Whatever the circumstances of an individual case, we have to, and will, protect the public.”
But on Friday, Home Secretary Sajid Javid went further, writing in The Times: “My message is clear - if you have supported terrorist organisations abroad I will not hesitate to prevent your return.”
2. How should Begum be treated by UK authorities?
Begum was a pupil at Bethnal Green Academy in east London when she ran away to Syria in February 2015 with Kadiza Sultana and Amira Abase, who also attended the school.
Tasnime Akunjee, a lawyer who was instructed by the girls’ families after they disappeared, told the Press Association news agency that British authorities should be reminded of former Metropolitan Police Commissioner Bernard Hogan-Howe’s position at the time.
Lord Hogan-Howe said that the girls would be treated as victims so long as they had not committed any further offences while in Syria.
But the Met’s former terror chief, Sir Mark Rowley, said on Thursday that his view had changed since his public plea for the schoolgirls to return home in 2015.
“What the police and security services will be doing now is a cold rational assessment of the intelligence. What risk does she pose to the UK?” he said.
“Police teams have been working hard to collect evidence from things collected on the battlefield, those who have returned, and social media.”
3. How many British women and girls joined Isis and how many have returned?
An absence of public government data has led experts to warn the number of women and minors linked to Isis thought to have returned has been significantly underestimated.
An estimated 850 people have travelled from the UK to support IS in Iraq and Syria, including 145 women and 50 minors, according to a report by King’s College London released last year.
Of the 425 who have returned, only two women and four minors were listed.
4. Do they pose a threat?
Dr Joana Cook, a senior research fellow at KCL who co-authored the study, said the researchers considered the women to be potential security threats based on several factors.
She said: ”[These include] the physical security roles and related training that women have undertaken in Isis-held territory, and the potential to transfer or apply these skills in other locations, or to pass these on to other people... including other women and their children.”
5. What is left of Islamic State?
When Begum left for Syria in 2015, Isis had taken control of large tracts of northern Syria and northern Iraq.
Millions of people were living in territory controlled by the terrorist group, which had declared the creation of a caliphate.
Four years later, following a massive military campaign by regional forces assisted by foreign powers including America, Britain and Russia, Isis territory has dwindled to a small village in eastern Syria.
Earlier this week, US-backed Syrian forces launched an operation to clear Baghuz where, according to Begum, Abase and a fourth Bethnal Green schoolgirl, Sharmeena Begum, remain.