He said there was little difference between the Bloody Sunday killings and the 1971 Ballymurphy case.

The killings took place during the Army's Operation Demetrius - the arrest of those who would be interned on suspicion of involvement in paramilitary activity.

Soldiers claimed at the time that they had opened fire after being shot at by republicans.

The victims included a Catholic priest, Father Hugh Mullan and a mother-of-eight, Joan Connolly.

Mr Adams said: "It is my strong view that the difference between Bloody Sunday and what happened in Ballymurphy is that Bloody Sunday happened in half an hour almost in the presence of television cameras.

"Of course what happened in Ballymurphy happened over 36 or 48 hours and in the middle of internment and the immediate aftermath.

"The case that has been put is irrefutable, it is very, very clear that there was a killing operation in Ballymurphy and that the Paras came in and ironically enough exactly the same Paras went into Derry a short time after.

"The families want an independent international investigation, they want the British government to apologise for what it did and they want the support of everyone interested in truth and justice."

A mural was unveiled on Thursday commemorating those who died in the incident.