The HSIB visited 18 hospitals and found that the situation on paediatric wards was "challenging" and "not safe" for children who were suicidal or at risk of harming themselves.

The HSIB started the investigation after a young patient on a paediatric ward tried to harm themselves and staff.

The child was waiting for a mental health assessment.

The HSIB's findings come after a series of BBC reports, including the story of 16-year-old Molly who has autism and spent several months on a children's ward.

Other families have also contacted the BBC with similar experiences.

The investigation found that hospitals are seeing an increasing number of children with a combination of autism, learning disabilities, and complex social and mental health needs.

NHS England says it has an ongoing transformation program to improve mental health services for children and young people, including adapting hospital environments for those with "sensory needs." The Healthcare Safety Investigation Branch (HSIB) found that paediatric wards in the NHS contain many risks for self-harm, including ligature points and are noisy and busy places that are unsuitable for children experiencing a mental health crisis or with sensory needs.

The report found that therapeutic help was limited or non-existent and children deteriorated as a result.

The report stated that on one paediatric ward there were more than 70 security incidents over three months relating to children with high-risk behaviours, most of which involved physical restraint.

The report also found that staff were concerned about the "negative psychological impact" it was having on other patients and their families.

HSIB also reported that there were many incidents where staff were assaulted and some hospitals were struggling to recruit and retain staff.

NHS England stated that they will review the concerns raised by HSIB and consider them as part of ongoing work to improve care for children and young people with mental health needs.