BBC News
By Noel Titheradge
image copyrightGetty Images
Social media groups involving teenage girls that led to "suicidal crises" and "serious self-harm" have been uncovered by police, BBC News has learned.
Twelve girls, aged between 12 and 16 years old and from across southern England, were part of an Instagram chat group whose name refers to suicide.
The group was discovered when three of the girls went missing and were found seriously unwell in London.
Instagram says it found no suicide or self-harm related content in the group.
'Serious self-harm'
BBC News has obtained a police briefing about the investigation which discovered the online groups.