A man has been arrested on suspicion of murder after four people, including three children, died in a house fire in Bradford.
Two girls aged nine and one, and a five-year-old boy, were taken to hospital but all died from their injuries, while a 29-year-old woman also died at the scene, West Yorkshire Police said.
Police believe the fire was started deliberately and the incident was domestic-related.
Officers were called by the fire service to reports of a house fire at a property on Westbury Road just after 2am on Wednesday, the force said.
Detective chief inspector Stacey Atkinson said: “This is an absolutely devastating incident in which three children and a woman have lost their lives.
“Our thoughts remain with their family, friends and loved ones.
“Early enquiries show that the fire was started deliberately, and we have arrested one man on suspicion of murder.
“He is seriously ill in hospital today as a result of injuries caused by the fire.
“While our enquiries are at an early stage, we do at this time believe the incident is domestic related.
“We are appealing anyone who was in the area at the time of the incident or who has CCTV or doorbell footage to come forward.”