The victims have called for a major investigation similar to the Ryan Report earlier this year that catalogued abuse by Catholic clergy in the Republic.

They are being supported in their call by DUP MP David Simpson, who has long called for a full public inquiry into the scale of clerical and institutional child abuse.

Sinn Fein has also backed a full probe.

A lawyer for the victims said they suffered sexual and physical abuse in cases dating back to the 1940s, but believed they have been discriminated against since inquiries in the south of Ireland did not extend to Northern Ireland.

Solicitor Joe Rice said he had written to First Minister Peter Robinson and Deputy First Minister Martin McGuinness, as well as Secretary of State Shaun Woodward, detailing the demand for an inquiry into child abuse in the jurisdiction over the last 70 years.

Mr Rice said many of his clients had approached him and other solicitors following the release of the Ryan Report.

"We have instructions from a significant number of clients who have been, and are, the victims of abuse, whether sexual, emotional, physical or through neglect, in numerous church and state-run institutions in Northern Ireland since 1947," the victims' letter read.

"It is apparent that the level of abuse was widespread and endemic and moreover that all the institutions involved had a duty of care to those children placed in their trust and responsibility under the different statutory frameworks in the post-war period."

Upper Bann MP David Simpson said the level of both clerical and state abuse needed to be established.

Mr Simpson said: "The Ryan Report uncovered abuse of children on a monumental scale in institutions run by religious orders and by the state in the Irish Republic.

"We need to know the scale of the problem of child abuse in similar institutions in Northern Ireland so that we can bring the guilty parties to justice and ensure that those affected receive the help that they deserve."

Sinn Fein MLA Sue Ramsey, who sits on the Stormont health committee, said her party supported the victims' call.

She said: "Victims in the north deserve to have their abuse and mistreatment acknowledged, there needs to be full accountability and restitution from the religious orders. They need to fully accept their moral obligation to the victims."

The Catholic Church last night issued a statement on behalf of the northern bishops.

It said that any decision to hold an inquiry must be made by the state.

The statement said: "Anyone who has concerns about child abuse should raise them with the civil authorities and, if they wish, with the church's National Office for Safeguarding Children, where these concerns will be dealt with appropriately."