A man and a woman have been arrested after a baby was found with serious injuries in the refuse area of a block of flats.
A 24-year-old woman has been detained on suspicion of attempted murder, while a 32-year-old man is being questioned on suspicion of assisting an offender, West Midlands Police said.
Both are related to the baby girl, who remains in a critical condition in hospital, a force spokesman confirmed.
Police were called to a flat on Boscobel Crescent in Wolverhampton on Saturday evening to a report of a missing child.
A very young baby was found nearby in the refuse collection area of the flats with serious injuries.
She was taken to Birmingham Children's Hospital where she remains in a critical condition, West Midlands Police said.
The force spokesman said they are investigating how the baby came to be in the refuse area and are conducting inquiries around the tower block.
Detective Inspector John Smith, from the force Public Protection Unit, said: "We are making a number of enquiries to establish how this young baby has come to sustain her injuries, and how she came to be found in the refuse area of the flats.
"The two people who have been arrested are related to the baby and we are currently not seeking anyone else as part of our enquiries. We urge anyone who has information to help our investigation to come forward at the earliest opportunity."
Anyone with information on the incident is asked to contact the Public Protection Unit at Wolverhampton Central police station on 101.