The incident took place yesterday when the girl was alone in the house. The five accused barged into the house and threw kerosene and set her ablaze, circle officer C P Singh said.
The victim suffered about 90 per cent burns and has been referred to a Delhi hospital for treatment, he said.
According to the victim's family, property dispute was the reason behind the incident, though investigations so far have found that the girl was having an affair with the married son of the neighbours and had often been warned against continuing the relationship, Singh added.