Security measures are being ramped up in Belfast city centre following an explosion outside a busy restaurant that could have killed festive revellers.
With thousands expected to hit the capital's high streets on what is to be one of the busiest Christmas shopping days of the year, police have appealed for vigilance.
And businesses are continuing to urge people to support trade by venturing into the centre.
The city was left reeling after the bomb exploded in the bustling Cathedral Quarter district just before 7pm last night. No-one was injured in the blast.
Police were in the process of evacuating around a thousand people from bars, eateries, residential accommodation, a theatre and a hotel when the bomb exploded.
They were responding to a bomb warning phoned through to a Belfast newsroom.
A spokesman for the Police Service of Northern Ireland (PSNI) said today security would be stepped up to prevent a further attack on the city.
Police have been stopping cars and checking car boots at the entrance of Castle Court Shopping Centre in the city since last month.
Other security checkpoints were set up throughout Belfast after a man was forced by masked dissidents to drive a car bomb to a shopping centre that faces a police station last month.
That 60kg (132lb) device only partially exploded and no-one was injured.
In a separate statement today, the PSNI requested member of the public in north and west Belfast particularly to be vigilant over the coming weekend, and to report any suspicious behaviour.
The scene of the blast had been cleared this morning. There was no sign there had been an explosion - bar a slight black mark on a wall.
Police said last night that the person who made the warning call wrongly claimed the device had been left at a hotel, when it was actually placed on the pavement beside a restaurant.
Dissident republicans opposed to the peace process have been widely blamed for the attack.
While police described the explosion as "small" they said the device still had the potential to inflict lethal injuries.
In November dissidents were also blamed when a bus driver in Londonderry was forced to drive a bomb to a police station in the city. She abandoned the vehicle before reaching the destination and the device did not explode.
While the threat posed by the violent extremists has remained classed as severe, police have acknowledged a "surge" in activity has taken place in recent weeks.
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The Irish News newspaper, which received the bomb warning, said the caller claimed to represent terror group Oglaigh na hEireann.
Irish Taoiseach Enda Kenny joined police, political and church representatives and traders in condemning the attack.
"I condemn this atrocity as a mindless attack on the sanctity of human life, carried out by people whose depraved agenda cannot, and will not, be allowed to gain a foothold in Northern Ireland," he said.
"We must remain ever vigilant in ensuring that peace in Northern Ireland is maintained, and that it continues on its path to becoming an ever more progressive society."
Northern Ireland First Minister Peter Robinson and Deputy First Minister Martin McGuinness have described the bomb attack as "despicable".
Mr Robinson said he condemned it in the strongest possible terms.
"Once again we are witnessing the work of a mindless minority who are intent on taking the heart out of the city and wreaking havoc on the lives and businesses of the people of Belfast and Northern Ireland," Mr Robinson said.
Mr McGuinness said those responsible had shown a complete disregard for human life.
"Their actions have done nothing to move our society forward but instead have caused distress to local residents, disruption to Christmas revellers and loss of revenue for surrounding businesses," he said.
In a joint statement, both ministers appealed with anyone with information to contact police.