A teenage girl has been killed in southern Italy and 10 other students wounded by a bomb that exploded in front of school.
The explosion occurred near the entrance of the school in Brindisi on Saturday as girls were arriving to start lessons.
Melissa Bassi, 16, died in the blast and one of the injured was in a very serious condition. Two others also required surgery, while five of the injured were sent home from hospital after treatment.
Authorities said at least two gas canisters appeared to have been placed in or near rubbish containers.
Investigators said the rudimentary nature of the bomb and the targeting of an all-girls secondary school did not point toward organised crime. There was no claim of responsibility.
Schools in the region were immediately closed, and a residents held a rally in the city's main square to express disgust at the attack.
Brindisi mayor Mimmo Consales initially blamed local mafia known as the United Sacred Crown but later said it looked more like the act of a "crazy man".
The school where the blast took place was named after the wife of murdered anti-Mafia judge Giovanni Falcone.
Mr Consales noted the attack occurred just a few days before the 20th anniversary of the murder of Mr Falcone and his wife in a bomb explosion in Sicily on 23 May, 1992. An anti-Mafia march had been planned in Brindisi later in the day.
After a meeting of investigators, the region's top anti-mafia magistrate Cataldo Motta told reporters "coincidences may only be coincidences... It may not be an organised crime group."
The homemade bomb, detonated with a timer, did not match past mafia-related blasts, where high explosives were set off by remote control.
Twenty years ago the Sicilian Mafia planted bombs in Milan, Florence and Rome, killing 10 people, in response to a crackdown on organised crime that had been spearheaded by Mr Falcone and his fellow magistrate Paolo Borsellino, who was also assassinated in 1992.