A woman arrested following the death of a young child at a property in south Wales on Friday 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.
She has been named locally as Amelia Harris, aged three.
A 37-year-old woman was detained by officers and taken to Merthyr Tydfil police station.
She remains in police custody and is currently assisting officers with their enquiries, police said on Saturday.
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.”
As part of the investigation near Tonypandy, Brithweunydd Road has been closed off.
Rhondda MP Chris Bryant tweeted on Saturday: “Very disturbing events in Trealaw last night.
“I’ve spoken to police and my gratitude goes to the paramedics and police who have been dealing with what must have been very upsetting scenes.”
Anyone with information is urged to call police on 101 or call Crimestoppers anonymously on 0800 555111, quoting reference 1800207700.