A woman has been arrested on suspicion of murder after two children died at a home in Stoke-on-Trent.
The boy, 11, and girl, seven, were found injured and died at the scene.
Police discovered the children when they visited the house after first being called to the stabbing of a man at a car wash nearby.
A woman, 49, known to the children, was arrested in connection with the stabbing and then on suspicion of murder.
The children were found at an address on Flax Street at about 14:15 BST on Sunday, after a call-out to the car wash on Campbell Road slightly earlier.
The stabbed man, in his 40s, was treated in hospital, but has since been discharged.
Staffordshire Police has referred itself to the police watchdog, the Independent Office for Police Conduct due to the force’s recent contact.
Det Ch Insp Cheryl Hannan said: “We don’t believe there to be any wider threat to the public at this time.
“Our focus remains on finding out more about what happened yesterday and supporting the family at this deeply distressing and tragic time.”
The children’s family have been informed and are being supported by specially trained officers, the force said.
Detectives are appealing for witnesses and anyone with CCTV or dashcam footage from the area of Flax Street and Campbell Road between 13:30 BST and 14:30 on Sunday to come forward.
West Midlands Ambulance Service said the children were found in a critical condition and despite the crew’s best efforts, they were confirmed dead at the scene.