ROME - Italy was shaken on Saturday by a fatal bombing attack against young students, which killed one girl and injured several others outside their school in the southern city of Brindisi.

Melissa Bassi, 16, was killed by an explosion caused by three gas devices placed near the vocational school "Francesca Laura Morvillo Falcone" while other seven female students were transferred to hospital, of which one was in "serious peril of life."

The victim and her schoolmates had just got off a bus and were about to enter the school shortly before 8:00 am local time, when a violent explosion hit the group near the entry gate of the school in the city center.

Local police, authorities and citizens rushed on the spot described the situation as "dreadful."

"The scene was chilling, the ground sprinkled with debris and books. There is no doubt that it was an attack organized for massacring students," regional councilor for policies on youth Nicola Fratoianni told Rai state television.

"I saw one girl whose body was widely burnt shouting the name of her best friend Melissa, who then died. It was shocking," said one of the survived students.

Political and judicial authorities blamed the local mafia for the unprecedented attack, which, according to police sources, was activated by a timer. However, there was no concrete information as to who might be behind the attack for the time being.

Analysts noted that the school was named after the wife of Giovanni Falcone, an anti-mafia magistrate. The magistrate and his wife were killed along with three bodyguards in a mafia bomb attack on May 23, 1992.

In addition, the institute had been the winner of the first edition of a local legality award, and is located in front of a court where an anti-mafia march was supposed to take place on Saturday.

"Mafia feels hatred for young anti-mafia movements, because it is through education that the most effective fight to mafia is carried out," former national anti-mafia prosecutor Piero Luigi Vigna said.

"This time the target was a school dedicated to a symbol of anti-mafia fight, and especially attended by girls, who are a fundamental cultural vehicle," he stressed, adding "the attack looks as a strength affirmation" typical of the organized crime, aimed at hitting the state especially in difficult times.

According to noted anti-mafia prosecutor Antonio Ingroia, the fact that the attack was carried out against Italy's young generations was a "destabilizing factor for the national security."

"And it is even more worrying in this moment of economic crisis, as a security crisis risks to add up to the economic crisis," Ingroia told Xinhua.

It was the most serious terrorist act since 1992-1993, and "carries all the flavor of the mafia matrix," he said.

Earlier this week, Italy has announced a plan to increase counter-terrorism intelligence following an escalating series of letter-bomb threats and petrol-bomb attacks amid growing tension over government austerity measures.

According to latest data released by the interior ministry, a number of 14,000 sites are currently considered potential targets in Italy and more than 550 people are already under special protection.

Italian Prime Minister Mario Monti, while attending the G8 summit in the United States, said his government was determined to fight crime and prevent a return to the country's "subversive tendencies."

In a statement, Italian President Giorgio Napolitano called for rapid and effective investigations to identify those responsible for Saturday's "bloody attack on civil society" stressing the state will strongly fight "any outbreak of subversive violence."

Government ministers expressed their consternation and condemnation of the act, while national police head Antonio Manganelli promised he "will give no respite to authors of the vileness."