Police in Northern Ireland have begun a major investigation into long-term abuse of children and young adults who had been in care.

Edwin Poots, the health minister, said the allegations were on a scale with recent scandals in Rochdale and Oxford.

Police have identifed 22 young people they believe may have been at risk. The people were in care but the alleged abuse is understood to have taken place outside the care system.

The police said in a statement that officers had become "increasingly concerned about the issue of child sexual exploitation following an internal review".

"As part of this review, we have identified a group of 22 young people who may be at risk from child sexual exploitation and are seeking to identify those who may have committed crimes against them."

Paul Givan, the chairman of the justice committee, described the reports of child sexual exploitation as "gravely disturbing".

"The horrors of these crimes leave us only to pray for the victims and work towards ensuring the perpetrators are brought to justice," he told the BBC.

"The public will be deeply concerned at this development and need to hear from the relevant authorities as to what has happened."

The abuse investigation is due to be discussed at Stormont on Monday, in a joint meeting of the assembly's health and justice committees.

Poots and justice minister David Ford are due to attend the meeting which was called by Givan.

Givan said the meeting would provide "an opportunity to probe what actions are being taken to investigate and bring to justice those responsible".