A murder investigation has been launched after two women were found dead at a house, police said.
Officers were called to Ireton Court in Thame, Oxfordshire, at 2.21am on Sunday where the pair were found with fatal injuries, Thames Valley Police said.
A third woman was taken to hospital but her condition is not thought to be life-threatening, a police spokesman said. The ages of the victims have not been released.
A man was arrested on suspicion of murder in Thame Market Place shortly afterwards and he is being questioned at Abingdon police station.
The police spokesman said: "Nobody else is being sought for questioning at this time."
Police and forensic investigators were at the scene as neighbours spoke of their shock at having a murder inquiry in their "delightful" town.
Police said it appeared the two women who died may have sustained stab wounds.
Post-mortem examinations are due to be conducted on their bodies as the third injured woman remained in hospital for treatment.
The suspect is a 21-year-old man, a police spokesman said.
All parties are said to be known to each other but their relationship has not been disclosed.