A girl of 15 was raped at a train station in Birmingham before being sexually assaulted by the driver of a car she flagged down to help her.
Detectives called the two attacks at Witton station "horrifying" and said they were launching a major manhunt.
The teenager was with a friend when she was approached by a man who led her to a secluded part of the station and raped her.
Shortly after she flagged down a passing car and was assaulted again.
British Transport Police and West Midlands Police are treating it as two separate reports of rape.
The first attacker is described by police as an Asian man in his early 20s with light skin, brown eyes, skinny build and about 6ft tall.
Police said the second man was also Asian and in his early 20s and about 5ft 6in to 5ft 7in tall. He was of a large build, with a beard and wore a blue jumper and black jeans.
The attacks happened between 19:00 BST on Tuesday and 02:00 on Wednesday.
CCTV has been seized and is being investigated.
Det Ch Insp Tony Fitzpatrick said: "This was a horrifying ordeal for this young girl and we have specially trained officers supporting her.
"It is now vitally important we investigate exactly what happened on Wednesday morning as well as identifying offenders for both of these awful incidents.
"I would be keen to speak with anyone who may have been in the area at the time. If you were passing by the station and saw two girls walking with an older man, then please get in touch immediately.
"Likewise, if you saw any suspicious vehicles close to Witton station close to 2am then please get in touch as soon as possible. Your information could prove vital in our enquiries to identify the perpetrators."