A jihadist and her four year old son were able to travel from Syria to Sweden despite the mother having joined the Islamic State (ISIS/ISIL) and the son appearing in an Islamic State propaganda video, unnamed sources told The Sun. Khadija (formerly Grace) Dare, born in London, smuggled her son Isa, who had become ill, to Sweden to get surgery.

It is not known how they got out of Syria, or how it is possible that they were not stopped on their way to Sweden.

"Isa had to have an operation weeks ago," the source said. "He and his mother were in Sweden after she left Syria, but no one knows how she managed to get out. She had a Swedish husband with ISIS. He is the connection to the country. She may have used another identity to get there but Isa is very recognizable, so it was quite a feat. She was not detained or stopped , which is incredible given their notoriety."

If the information is correct, it is absurd that the pair were able to travel all the way across Europe without being stopped. Either Dare was able to enter Europe on her British passport, in which case it is outrageous that she was not picked up, or she entered Europe on a forged passport made in Islamic State territory, which proves that ISIS operatives are able to forge good enough passports to fool European authorities.

If she was able to enter Europe without a passport at all, coming in at night by boat into Greece or Italy, then it highlights the insecure nature of the Schengen Zone. Once inside the 26-state zone, border controls are minimal, with limited controls only having been reintroduced between certain countries following the Paris attacks.

It is possible that this is a fluke, a temporary breach of security, a mistake. But with so many refugees entering Europe, the sheer volume makes mistakes that much more likely. European voters are increasingly worried about the lackluster security at their borders and cases like this will increase those worries.

It is not known whether she plans to return to the Islamic State.

"Her whereabouts are unknown," the source added. "But, as far as anyone knows, Sweden was the last place she has visited. I don’t think she’ll return to Britain because she’s so afraid of getting caught."

The boy's grandfather, Henry Dare, told the Daily Mail that the boy had begged him "please save me" in a phone call just days before the child was forced to appear in an Islamic State propaganda video.

If Europe's security services are more vigilant, perhaps they could still save him.