A man is under arrest on suspicion of murder after a woman died and three others were seriously injured in a "disturbance" police said.
The 21-year-old suspect was held after officers were called shortly before midnight on Saturday to Llys Aderyn Du, a housing estate in Rhyl, North Wales.
Officers arrived with the Welsh Ambulance Service and four people were found with serious injuries.
All four were taken to Ysbyty Glan Clwyd Hospital by ambulance, but a woman was pronounced dead at the hospital.
After a search in the area the suspect, a local man, was arrested and is now in police custody for questioning. Police said they are not looking for any other suspects.
Superintendent Mark Pierce from North Wales Police, said: "Unfortunately this is now being treated as a murder investigation and our thoughts are very much with the woman's family at this time.
"This was an isolated incident that spilled over into the street in Llys Aderyn Du.
"Officers and ambulance staff were quickly on scene and started first aid. The quick action by local officers identified and located the suspect nearby who was arrested.
"Three individuals, two women and a man, currently remain in hospital with injuries that are described as serious but not life threatening. The investigation is well under way and we will be conducting house-to-house inquiries throughout the day. "
Anybody with information is asked to contact North Wales Police urgently by either calling 101, or contacting the control room via the live web chat facility quoting reference number V138247.