The woman had reached Kanpur from Ahmedabad and had gone to the bus stop early morning to take a bus for her village in Hamirpur, station house officer Unnao police station Arvind Singh said.
She was walking on the roadside, when a SUV approached her and two youths, hailing from her native village, offered her a ride, he said.
There were three more men inside the vehicle who pulled the woman inside and drove off, the official added.
She was taken to a district hospital where the doctors confirmed the sexual assault, he said.
A case has been registered on charges of abduction and gang-rape, he said, adding investigation into the matter was on and efforts were being made to establish the identities of the accused who have not been arrested so far.