Insisting again that he did not want to hurt anyone, Ousseynou Sy, a 47-year-old of Senegalese origin, reportedly told investigators: "I heard the voices of the children in the sea who were telling me 'do something spectacular for us without hurting the children'."
Earlier Friday other reports quoted Sy as saying he planned to use his young passengers as human shields and escape to Africa.
"I wanted to get to the runway at (Milan's) Linate airport using the children as human shields and from there head to Africa by plane," Corriere della Sera daily quoted Sy as telling investigators.
Sy on Wednesday hijacked a bus while taking 12-13 year-olds from a gym to school in Crema, east of Milan.
Armed with two petrol canisters and a cigarette lighter, he threatened the youngsters, took their telephones and told the adults to tie them up with electric cable.
Their 40-minute ordeal ended when police managed to smash windows open and get those onboard out just as Sy set fire to the vehicle.
He now faces having his Italian citizenship, obtained through marriage in 2004, revoked.
According to the Corriere della Sera, Sy has told investigators he hates white people for having "invaded and colonised" Africa, forcing Africans to emigrate and "die in the Mediterranean".
Alberto Nobili, head of Milan's counter terrorism police, said Sy had posted a video on Youtube with the message: "Africa, rise up."
Media reports quoted him as saying he had no regrets as "it was something I had to do and would do again, 100 times. Why did I do it? To send a signal to Africa".
He reportedly told investigators that Italy's impounding Tuesday of migrant rescue ship "Mare Jonio" off the Italian island of Lampedusa with 48 people aboard had been a tipping point for him.
Quoting three students on the bus, Messagero daily reported Sy had first attempted a hijack on Monday, two days earlier.
"He tried to change the route but a teacher intervened and said 'what are you doing? Stick to the right route'."
That day, the trio said, Sy appeared very nervous, shouting insults at one child.
The government, in the shape of deputy prime minister, Luigi di Maio, and far-right Interior Minister Matteo Salvini, say Rome could now revoke Sy's passport.
The debate has become increasingly heated in a country where Salvini's tough anti-immigration stance is popular with conservatives.
In February last year, Italy was similarly rocked when far-right militant Luca Traini fired on a dozen African migrants in the central town of Macerata, injuring six. The attack was an apparent response to the killing of a young Italian woman, allegedly by a Nigerian drug dealer.
The alleged perpetrator of last week's Christchurch massacre in New Zealand had scrawled Traini's name on one of his weapons.
Anti-mafia state prosecutor Cafiero de Raho warned La Stampa daily the time had come to "tone down" the rhetoric, citing the danger of people further feeding on existing extremism and racial hatred.
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