One man has been shot dead and another injured, police have said.
The killing happened in the Fishermead area of Milton Keynes, Buckinghamshire, shortly after 10pm.
Detective Superintendent Rob Mason, who is leading the investigation, said: "Clearly we are at the very early stages of our investigation into this incident, which happened at Fishermead Boulevard.
"A large area of Fishermead is currently sealed off while officers carry out investigations and protect the scene.
"I can confirm that one man has died from his injuries and that another has been injured in the incident.
"I appreciate that residents will feel concerned about this incident. However, there is a large and highly visible police presence in the area.
"I also appreciate that there will be a lot of rumour and intrigue in the community. However, we are at the very early stages of this investigation and as such cannot speculate on possible reasons for the attack.
"I would ask that anyone who has any information about this incident contacts Thames Valley Police urgently."