A woman has been arrested on suspicion of murder after three children were found dead at a property in Bristol.
Officers attended a concern for welfare call in Blaise Walk, in Sea Mills, on Sunday at around 12.40am, Avon and Somerset Police said.
Three young children were found inside the property and were pronounced dead a short time later.
The 42-year-old woman has been arrested and she is in police custody at hospital.
Avon and Somerset Police has notified the Independent Office for Police Conduct (IOPC) due to prior contact.
Neighbourhood Chief Inspector Vicks Hayward-Melen said: “This is an incredibly tragic and heartbreaking incident in which three children have sadly died.
“My sincere condolences go to the children’s loved ones and we will be ensuring they are offered support through our family liaison unit.
“We believe this to be an isolated incident and there is no further risk to the wider community, however officers will remain at the scene to provide reassurance to anyone who has any questions or concerns.
“Over the coming days, residents can expect to see an increased police presence and we thank them for their cooperation during this time.”
A police cordon was in place across the street on Blaise Walk on Sunday evening.
There were police vehicles, and uniformed officers making house-to-house inquiries in nearby properties.
A woman, who did not wish to be named, described the arrested woman as "lovely".
She said the family had two boys, aged around eight and six months, and a girl aged around four.
"She was so happy when she had that little boy," she told the PA news agency.
"We were so happy for her, we came round and gave gifts. I'm very surprised because she was really gentle, really lovely.
"She always had a smile on her face. After the baby she was having a really hard time."
She said the woman was Sudanese, as well as her husband.
A 42-year-old Bristol taxi driver said he had last seen the mother and her three children - who he believed were aged eight, four and one - two weeks ago.
He said: "She was happy. Her kids were all happy."
The man said the family were part of the Sudanese community in Bristol.
He added: "She is a very nice person. It is very sad."
Sea Mills Primary School announced it would be closed on Monday morning and reopen at 1.30pm.
Marvin Rees, the directly elected mayor of Bristol, said: "It's almost impossible to find the words to describe this afternoon's devastating news from Sea Mills, Bristol.
"My thoughts are with all who knew these three young children. We will be working with schools, the community, and Avon and Somerset Police to support people."
Mark Shelford, the Avon and Somerset police and crime commissioner, said: "I am deeply saddened by the news of the deaths of three children today in Sea Mills.
"The deaths of these children is heart-breaking. My thoughts are with all those who knew and cared for these children and with the local community, who I know will be impacted.
"The police have made an arrest and believe this to be an isolated incident. They have assessed that there is no further risk to the wider community.
"There are questions to be asked about how such an appalling event has occurred and what could have been done to prevent it, but for now, I ask that people allow the police to investigate."
Darren Jones, Labour MP for Bristol North West, said: "I'm deeply saddened by this tragic news from Sea Mills today.
"My thoughts and prayers are with the friends and family of the children, and my thanks go to our emergency services who responded.
"Avon and Somerset Police will remain in the area but consider this to be an isolated incident."
An IOPC spokesman said: "We were notified this afternoon about this tragic incident in Bristol by Avon and Somerset Police, who advised us that there had been prior police contact earlier this month.
"We have requested a paper referral with further information about the prior contact and once received, we will assess it to determine whether further action is required from us."
