Two 17-year-old boys died after being stabbed in Milton Keynes.
Emergency services were called to an estate in Arford Croft, in the Emerson Valley area, just before midnight, Thames Valley police said.
One of the victims died at the scene and the other died after being taken to hospital.
Two men were injured in the incident and were taken to hospital with serious but not life-threatening injuries. There are no arrests.
Police officers remain at the scene, which is a culture of residential property.
"Police in Thames are in the early stages of a double homicide investigation after two teenage boys were tragically killed in this shocking incident," said Detective Ian Hunter.
"I would like to speak to anyone who has any information that might help with our questions or anyone who has witnessed any suspicious activity.
"Even if you think the details may be insignificant, please go out and talk to the police."