Two French teenagers are being investigated for murder after a girl, 14, was found drowned in the River Seine near Paris.
A boy and a girl, both 15, from the Val d'Oise area north of the French capital, were presented before a judge on Wednesday.
"Two minors are under investigation for murder, premeditated homicide," prosecutor Eric Corbaux told reporters.
The victim was fished out of the water on Monday evening by police, after an alert from the mother of one of the suspects.
In a case that has shocked France, the country's government condemned the girl's deaths as "utterly terrible and despicable".
"She was a victim of bullying, of a downward spiral that led to this drama," said government spokesman Gabriel Attal, vowing that those responsible would be punished.
According to prosecutors, the victim and two suspects knew each other and all attended the same private vocational school in Argenteuil, near Paris.
The Cognacq-Jay high school said in a statement that there was "tension between these three students after the victim's phone was hacked and compromising photos were posted by her two classmates".
The two detained teenagers were already facing disciplinary action for their previous behaviour towards the victim, the school added.
Prosecutors say the three teenagers met in Argenteuil on a dirt road away from housing, between the Seine and the railway tracks.
There, the 15-year-old boy is alleged to have beaten the victim, before throwing her still conscious into the river with the help of the 15-year-old girl, where she drowned.
The two teenage suspects were arrested on Monday and have remained in custody.
Due to their age, they face a maximum prison sentence of 20 years if convicted, as opposed to life imprisonment.
A march in memory of the murdered schoolgirl is due to be held in Argenteuil this weekend.