No injury marks have been found on the bodies of the two teenage girls who were found dead in Uttar Pradesh's Unnao and the cause of their death could not be ascertained in the autopsy, Uttar Pradesh Police Chief Hitesh Chandra Awasthi said on Thursday. A third girl, who was found in a field along with the two, is undergoing treatment at a Kanpur hospital and her condition is "critical but stable", he said.