A woman who was raped earlier this year, was set on fire by the same men out on bail on Thursday.

The sight of the rape victim set afire and running for help early Thursday sent shivers down the spine of local people.

Ravindra, who sitting by the roadside then, told reporters that he was so frightened that he actually went to pick up his stick.

"It was only when she came nearer that I found she was severely burnt," he said. She had been calling out for help, he added.

Ravindra said he called police and the woman herself talked on them on the phone.

The police arrived soon and she was taken to the local community health centre, he said.

She was later transferred to a district hospital and then to Lucknow.

The woman, who suffered 90 per cent burn injuries, was flown to Delhi in the evening for admission at Safdarjung Hospital, officials said.

Five men who allegedly set her ablaze were arrested.

Two of them were accused of raping her last year. One of the two was arrested then but recently let out on bail, police said.

The rape victim was on her way to Rae Bareli to attend a court hearing when she was attacked.

Inspector General (Law and Order) Pravin Kumar said in Lucknow that the police would seek fast track prosecution in the case.