A 13-year-old boy and a 27-year-old man have been arrested on suspicion of murdering a woman who was stabbed in the street.
The 25-year-old was attacked at 20:30 GMT on Saturday in Wellingborough Road, Rushden, Northamptonshire.
Paramedics were called but she died at the scene, near St George's Way.
Police said the arrested man has serious injuries, and another 27-year-old man was being questioned on suspicion of his attempted murder.
Det Insp Pete Long, said: "This was an extremely tragic incident in which a young woman has lost her life and I want to reassure people that we are doing all we can to bring those responsible to justice.
"A large team of detectives have been working on this case around the clock and a number of lines of inquiry are being pursued as part of this fast-paced investigation.
"This incident has really shocked the Rushden community, many of whom were on the scene last night, and I would ask anyone who was there and saw what happened to please come forward with your information."