Witnesses to the incident late Tuesday said the man approached the woman aboard the bus, spoke to her briefly, doused her with fuel and set her on fire.
The attack caused panic aboard the bus in the capital's Miraflores district, as passengers stumbled out the doors or threw themselves through the bus windows, witnesses told Peru21 newspaper. The driver used a fire extinguisher to save the victim.
The attacker escaped in the confusion.
Peru's ministry for women described the incident as an "attempted feminicide" and said it was providing assistance to the victim.
"A team of specialists is in the hospital to provide care to the woman, a victim of attempted feminicide," the women's ministry said in a statement.
The 10 injured passengers were treated for burns in the city's Loayza hospital.
Miraflores mayor Jorge Munoz said on Twitter he was "dismayed by the reprehensible act committed by a coward a few minutes ago against a woman, by setting her on fire when she was on a bus."
He said local authorities were putting themselves at the disposal of the police so that the attacker is caught "and punished with the full weight of the law."
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
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