The girl had been on the international wanted list since Wednesday when her family reported that she had left Sweden to join up with Isis in Syria, Swedish newspaper Expressen, which broke the story reported.
“The girl was reported missing earlier in the week and she was then put on all wanted lists, even internationally,” said Torbjörn Lindqvist, duty officer for Linköping police.
The girl was reportedly arrested in Vienna, Austria, on Saturday afternoon. This was due to her family having managed to track her phone, and then informing the Austrian police.
“According to the family, the girl has been radicalized in recent times. She has watched several videos that are linked to Isis, and talked positively about Isis in certain contexts. The family has also found notes in which she expresses support for people who have been indicted in the UK for having connections to Isis,” Lindqvist said.
“She cannot understand to what danger she’s exposed herself; she's been totally brainwashed by them,” one of the girl's cousins told Expressen.
The girl was born and raised in Sweden and attends high school.
“I've barely slept in three days,” her anxious mother told the tabloid.
A close family friend, who’s one of the leaders of the local community, told Expressen that the community will continue to have close links with the police to try to ensure that incidents like this do not happen again.
“It was us that contacted police, when we realized what had happened,” she said. “We really hope that we can cooperate more with the authorities, so we can prevent this kind of thing in the future.”
Previous statistics from the Swedish security service, Säpo, suggest that just over 300 Swedish nationals have left the country to travel to fight with Islamic extremist groups in Syria and Iraq.
Sweden's government is considering drafting new legislation that would ban its nationals from fighting in armed conflicts for terrorist organizations such as Isis.