The two girls, identified as Israe, 15, and 16-year-old Louisa, disappeared from their school in Haute-Savoie in the French Alps on Friday, prompting the police to launch a search for the pair.
The teenage girls were spotted leaving the Carillons de Seynod High School, located on the outskirts of the town of Annecy, at 1pm on Friday, March 4, according to public prosecutors.
The girls’ classmates began to worry about their whereabouts and made an attempt to intercept them at the Chambéry train station. When that failed, they alerted authorities at around 7.30pm.
Public prosecutors said they had reason to suspect the girls wanted to leave for Syria and had plans to get on a Paris-bound train from Chambéry.
However on Sunday night, the public prosecutor in Annecy confirmed that both girls had returned home by Sunday evening – Louisa during the afternoon after hearing a TV appeal from her mother, and Israe a few hours later.
Israe was already known to authorities as "radicalised", and had been placed in foster care and banned from leaving the country. A travel ban was put in place for Louisa on Saturday.
Israe's mother Nadia told Le Parisien newspaper that she had caught her daughter trying to leave for Syria two years ago.
"It is not easy to break this cycle... she has been sucked in by it," Nadia told the newspaper. "She wanted to go to Syria to help children and serve a good cause."
Following the incident, Nadia had alerted the authorities and Israe was enrolled in a deradicalisation programme.
Dounia Bouzar, who runs the anti-radicalisation centre Israe attended, said the 15-year-old had recently left a psychiatric hospital where she had been treated for "teenage depression". She described Israe as "fragile" and suicidal.
Louisa's uncle dismissed any allegations that his niece was intent on travelling to Syria, describing her as simply a "runaway".
French intelligence services have reported an increasing number of girls among the teens departing for Syria. They reported that among the 81 French minors who have left for Syria, a majority (51) are female.