A “small number” of British children have left Syria and returned to the UK via third countries in the last year, the government has said.
But British officials were not involved in helping them leave the country.
It follows the death of Isis bride Shamima Begum’s newborn son last month, which raised questions over the government’s repatriation policy.
The Home Office said local authorities and police could use their existing powers to help protect the children.
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In response to a written parliamentary question, Home Office minister Baroness Williams of Trafford said: “We can confirm that in the last 12 months there have been a small number of British children who have left Syria and returned to the UK via third countries.”
She said the government did not have a consulate in Syria and it advised against all travel to the country.
“We will not put British officials’ lives at risk to assist those who have left the UK to join a proscribed terrorist organisation,” she continued.
“If a British child who has been in Syria is able to seek consular assistance outside of Syria, then we would work with local and UK authorities to facilitate their return if requested.”
Earlier this year, Ms Begum – who left London aged 15 to join Islamic State in 2015 – gave media interviews from a Syrian refugee camp in which she said she wanted to return home.
But she was stripped of her British citizenship by Home Secretary Sajid Javid in an effort to stop her returning to the UK.
Ms Begum gave birth to a baby boy in the refugee camp, who was deemed a British citizen, but he died just three weeks later of pneumonia.
The government faced criticism in the wake of the death, but Foreign Secretary Jeremy Hunt said it would have been too dangerous to rescue the child from the camp.
The home secretary has defended his decision to revoke Ms Begum’s citizenship.
Details have also emerged of two more women from the UK living in Syrian camps with young children who have been stripped of their citizenship.
Mr Javid has previously indicated hundreds of children may have been born to so-called foreign fighters.
Around 900 people are thought to have travelled from the UK to engage with the conflict in Syria.
Around 20% of those have been killed overseas, while around 40% have returned to the UK.
A “significant proportion” of returnees are no longer considered a security concern, according to the Home Office.
The department said in a statement: “Our support will be tailored to the needs of each individual child.
“Local authorities and the police can use existing safeguarding powers to protect returning children, support their welfare and reintegration back in to UK society and minimise any threat they could pose within schools and to their local community.”