PARIS (Reuters) - Two French teenagers are under investigation for murder after police fished the body of a drowned schoolgirl out of the river Seine, prosecutors said on Wednesday, in a case that has shocked France. Prosecutors said the teenagers, a boy and a girl, both aged 15, had met the 14-year-old girl, whom they knew, in Argenteuil, west of Paris. The boy had beaten her and then with his girlfriend’s help thrown her into the river, where she drowned. “Two minors are under investigation for murder, premeditated homicide,” Pontoise city prosecutor Eric Corbaux told reporters. Asked about a possible motive for the attack, Corbaux said there had been rivalry between the two girls and a theft of photos of the victim. All three had attended the same school. French media reported that the victim had been bullied at school and that nude pictures of her had been hacked and circulated on social media. The boy’s mother told BFM TV her son had had a brief relationship with the victim before he met his current girlfriend. “I think it was some kind of love triangle and they could not handle it,” she said. The victim’s mother said the two suspects had previously issued death threats against her daughter. “They have ripped out my heart,” she told BFM TV.