The girl was returning home on Saturday, when Ravi, the man, allegedly slapped her. He was joined by his father Chandu in the assault, SHO, Sadar police station, Manish Charan said. He added that the woman was earlier in a relationship with him.
In her statement, the victim alleged that Ravi poured kerosene on her but she could not see the person who set her on fire, the police officer said.
She was rushed to the hospital where she died of severe burns yesterday, the police said.
Ravi and his father are being interrogated and an FIR has been registered, he said.