Police and troops in the North were tonight on full alert amid fears of more terror strikes following a failed bomb attack on a high-security prison.
The 150lb bomb - abandoned without warning in a stolen vehicle outside Maghaberry Jail, near Lisburn, Co Antrim - has intensified concerns that dissident republicans have launched a renewed campaign.
The dissidents struck just days after police in Belfast intercepted a van bomb they believe was going to be left outside the offices of the Ulster Unionist Party near the city centre. This time the detonator exploded, but the bomb did not go off.
A senior security source said: "Security has been heightened at all police and military bases. Even before Friday, we knew they (the dissidents) were planning something major."
In last night's attack a white Mitsubishi four-wheel drive vehicle, stolen in Dublin a fortnight ago, was used to transport the bomb to Maghaberry.
"Had the bomb gone off, as intended, there would have been substantial damage and possible loss of life," Police Chief Superintendent Mr Roy Toner said.
He also confirmed a heightened state of alert in the Lisburn and greater Belfast areas.
The Lagan Valley Ulster Unionist MP Mr Jeffrey Donaldson, whose constituency includes Maghaberry, urged the British government to call a halt to its demilitarisation programme while rogue paramilitaries still pose a threat.
Indicating either Real IRA or Continuity IRA involvement, he said: "It seems it may have been the work of dissident republicans and represents a further threat to the peace process."
PA