A woman arrested following the death of a young child at a property in south Wales remains in police custody.
Emergency services were called to an address in Trealaw in the Rhondda at about 10.20pm on Friday, and the child was declared dead at the scene.
A 37-year-old woman was detained by officers investigating the incident and taken to Merthyr Tydfil police station.
She remains in police custody and is currently assisting officers with their enquiries.
Police have yet to release the age or gender of the youngster or the nature of the allegation against the woman.
South Wales Police said the death was currently being treated as unexplained.
The force urged people to be responsible when posting content on social media.
Chief Superintendent Dorian Lloyd said: "We are continuing to investigate the events that led to the tragic death of a young child in Trealaw yesterday evening and an incident room has been established.
"Specially-trained officers committed to providing support to the family and to the local community at this very difficult time, have been deployed.
"I am aware of the deep concern and upset locally, but would urge all members of the community to refrain from speculating on the incident and to demonstrate responsibility when posting content on social media.
"I encourage everyone to think carefully about the consequences of messages - when using social media - and how they may impact on others.
"Positive action will be taken against those who post messages that are abusive, threatening or insulting."
Anyone with information is asked to call police on 101 or call Crimestoppers anonymously on 0800 555111, quoting reference 1800207700.