The girl, who was wearing a school uniform, was snatched in a busy Oxford street at 08:25 BST on Wednesday.
She was found a mile away nearly fours later after knocking on doors.
The girl was abducted on Marston Ferry Road in the Summertown area of the city and driven away by two men in a small, silver hatchback, possibly a Volkswagen.
Police were later called by a member of the public to Cavendish Drive where the girl had knocked on doors.
Speaking at a press conference Det Supt Chris Ward, head of major crime at Thames Valley Police, said the victim left her house and walked along Banbury Road to Marston Ferry Road.
He said she was approached and possibly hugged, and that it may have looked relatively innocent to witnesses.
The men who abducted her were described as white.
Det Supt Ward appealed for any motorists with dashcams, or cyclists with headcams to come forward, saying the attack could only have happened in a "small geographical area".
He described the girl as "extremely traumatised, extremely upset" and the incident as "very, very, very unusual".
"The vehicle is key to this," he added.
It is not believed the girl knew her attackers.
Local police commander Supt Christian Bunt said: "I recognise that this is a very concerning incident for everyone in Oxford.
"This type of extremely serious crime is fortunately very rare in Oxford but is still very worrying.
"My local policing teams will be working hard in support of the major crime investigation.
"I am putting in place additional patrols to provide reassurance.
"We will also be working closely with the local schools to provide information and support."
A 14-year-old girl who was abducted while walking to school was raped by "more than one man", police have said.