Two teenage boys have died and four other children are receiving hospital treatment after a “serious incident” in Sheffield, police said.
Officers were called to a house in the Shiregreen area of the city at 7.30am on Friday.
South Yorkshire police said the boys, aged 13 and 14, had died and the other children, aged 11, 10, three, and seven months, were conscious in hospital.
Witnesses report seeing “two children being taken out of a home in bandages” and being put into a road ambulance while a man and woman were seen in handcuffs.
A 37-year-old man and 34-year-old woman have been arrested on suspicion of murder.
Of the four kids taken to hospital, one is a seven-month-old baby. The others are an 11-year-old, a 10-year-old and a three-year-old.
The cause of death of the 13 and 14-year-old boys has not yet been established and a post-mortem examination will be carried out in due course.
Detective Chief Inspector Simon Palmer, who is leading the investigation, said: “Detectives and specialist officers remain in the Gregg House Road area carrying out inquiries and we are working hard to ascertain the exact circumstances surrounding this incident.
“We will remain in the area this afternoon and into the evening carrying out enquiries and providing reassurance.
“I appreciate the events of this morning have caused concern locally but I’d like to reassure you that there is no wider risk to the community.
“We will be providing regular updates when we are able to. If anyone does have concerns, please do not hesitate to speak to an officer in the area.
“To allow the investigation to progress, I would please ask that people are mindful of what they are posting on social media and the potential distress this may cause.
“A 37-year-old man and a 34-year-old woman have been arrested on suspicion of murder in connection and remain in custody at this time.”