"The girls returned from work at 12.30am. While they were watching TV, someone knocked on the main door," police said.
"The security guard opened it without checking who it was. An armed gang of eight-nine men barged inside and forced all three security guards into a room. They then took three girls inside a room and raped them. They also looted the house," the police added.
The three victims were then taken to another house, where one of them was raped again.
One of the bar girls, on condition of anonymity, said the men forced all eight of them to strip and then made videos using their mobile phones, threatening to circulate the video clips if anyone informed the police.
Police suspect the miscreants had been following the girls for a few days.
"We suspect that the accused are from surrounding villages. We have formed several teams to crack the case," said Anupam Agrawal, superintendent of Ramnagar district.