Two people arrested in connection with the death of a teenage girl in a drugs-related incident have been released on bail, police said.
The 16-year-old girl died in the early hours of yesterday morning after taking a "yellow-white" paste thought to contain amphetamine.
Her death in York prompted police to issue an urgent health warning for people in the area not to risk taking any substances with a similar description.
Paramedics were called to a property in Tang Hall Lane, York at around 11.30pm on Thursday night and rushed the teenage girl, named locally as Poppy Rodgers, to York District Hospital in an ambulance.
She died despite attempts to resuscitate her.
Meanwhile, a 21-year-old man, also believed to have taken the substance, is still in hospital but is said to be improving.
A 23-year-old man and a 26-year-old woman, both from York, who were arrested in connection with the investigation have been bailed, a spokesman said.
The force issued the following safety warning: "In relation to this investigation, North Yorkshire Police and the North Yorkshire and York Primary Care Trust are urging anyone with drug-related health concerns to seek medical assistance without delay. Either contact your GP or go to straight to hospital if required.
"The yellow-white paste involved in this particular case is undergoing tests to determine exactly what it contains, although amphetamine is believed to be involved. Until this is confirmed, people are strongly urged not to risk taking substances matching this description or of a similar nature.
"One girl has already died and a young man is in a serious but stable condition at hospital, so the potential dangers are very real."
Inquiries were continuing at the address in Tang Hall Lane and witnesses or anyone with information is urged to contact North Yorkshire Police.
Neighbours have spoken of their shock at the death.
Simon Moss, chairman of Tang Hall Residents Association, said there had been problems at the property with loud music and people calling at the house at unsociable hours. He said he thought a woman lived at the property with four children.
Neighbour Tom Gibson said he heard loud music and fireworks being let off on the night of the incident. He said a woman and three girls lived at the address but the children had recently gone to live with their grandmother and had not been seen for 18 months.
"It is an absolute tragedy. I really feel for the parents of the girl," he said.
"Apart from last night there has been nothing unusual, apart from on occasion a bit of noise."
It is thought the dead girl, who has not been named, lived locally and was at the property on Thursday night.
Friends paid tribute to Poppy on Twitter.
Ally Law wrote: "My deepest sympathies to the family & friends of Poppy Rodgers xxx".
Georgina Taylor added: "Such as a sad loss.. so young... RIP Poppy Rodgers."
Jaaz Styles tweeted: "You were an incredible person, with a brilliant personality. I only spoke to you a few times but you were such a lovely girl x".
Meghan Onderdonk wrote: "wouldn't be the person I am today if you weren't such a big part of my life. RIPpoppy i love you."
Oliver Tuley posted: "Surreal seeing that on the news & such a shame, a life taken away when she had so much to live for rippoppy."
Sara-Leanne Win posted the message: "Poppy Rodgers... you will be missed. i love you angel, sleep tight sweetie."
It was reported Poppy was a student at York College.
Spokeswoman Jill Sissons told The Press newspaper: "We are saddened to hear of the death of Poppy Rodgers."
"The College was working with Poppy to engage her in education and our thoughts go out to her friends and family."
The headteacher at her previous school, King James's School in Knaresborough, paid tribute to her.
Carl Sugden told the paper: "Poppy was a well-regarded girl and was popular and had a good group of friends."