Downing Street issued details of the warnings given to a TV station and the Samaritans using recognised codewords and passed on to the RUC.

The Real IRA said in a statement admitting responsibility for the bomb, which killed 28 people, that its targets were commercial and it did not intend to kill civilians.

It disputed claims that the warnings were deliberately wrong to move people closer to the bomb, which was several hundred yards from the courthouse.

The statement said: "At no time was it said it was near the courthouse."

People had been moved from the courthouse, where police understood the bomb to be, when it exploded yards from shoppers.

Warnings in full

1432 A warning was telephoned to Ulster TV. The exact words used were: "There's a bomb, courthouse, Omagh, main street, 500lb, explosion 30 minutes."

1433 Ulster TV received a second call. The caller said: "Bomb, Omagh town, 15 minutes."

1434 A third call to the Samaritans at Coleraine. The caller said: "Am I through to Omagh? This is a bomb warning. It's going to go off in 30 minutes."

The caller then went on to say the bomb was on Main Street about 200 yards from the courthouse. No description of any vehicle was given.