Denis Murray on the reaction to the 'Real IRA' statement

Northern Ireland Secretary Mo Mowlam immediately condemned the apology as "pathetic".

In a statement released in Dublin on the same day that Prince Charles visited the scene of the bombing, the organisation said that the targets had been "commercial".

It added: "We offer our apologies to these civilians."

The group said it issued three warnings - "40 minute warnings on each of them".

"The location was 300-400 yards from the courthouse.

"At no time was it said it was near the courthouse," it added.

Mo Mowlam: 'Pathetic attempt to apologise'

Many of those caught up in the blast in the County Tyrone town on Saturday were moving away from the courthouse to the street where the blast occurred following the warnings.

Dr Mowlam condemned the statement as a "pathetic attempt to apologise for and excuse mass murder".

Mo Mowlam condemns "mass murder apology"

She said they were "murderers pure and simple" and people would have "absolute contempt" for their apology.

She added: "Responsibility for this atrocity rests entirely with the bombers."

BBC Northern Ireland correspondent Denis Murray on Prince Charles's visit to bomb-hit Omagh

BBC correspondent Denis Murray said: "Most people in Northern Ireland and around the world will be saying you can't just apologise for what happened on Saturday."

Security officials in Dublin and in Northern Ireland pointed the finger of blame at the Real IRA for last Saturday's explosion in the immediate aftermath of the blast.

BBC Northern Ireland correspondent Denis Murray: There is no indication that the Real IRA will reconsider its terror strategy

The group split from the Provisional IRA last year after the IRA declared a ceasefire allowing its political wing Sinn Fein to join peace talks which culminated in the Good Friday Agreement in April.

The Conservatives have called on the government to ensure no members of the Real IRA are freed from jail early as part of the Good Friday Agreement.

It would be insensitive to release prisoners in the immediate aftermath of the Omagh bombing, he said.

Mr Lilley said: "The sooner we take arms out of existence and circulation and availability to these groups, the better that must be for peace, security and confidence in the province."