A largely successful St Patrick's Day festival was marked with a bomb alert in University Street in Belfast.
Two controlled explosions were carried out on a device inside a car.
Former Pogues singer Shane MacGowan had been due to perform at the Menagerie Bar when the alert began.
Pub owner Francie Mackin said: ``We have been preparing ourselves for the last couple of months to provide good entertainment for people, with top names and top DJs.
``For this to happen is really a blow to St Patrick's Day.''
But organisers of the St Patrick's Day carnival in Belfast pointed out that tens of thousands of people had attended the carnival and there weas relatively little trouble. They said carnival stewards had played key roles in defusing drunken skirmishes.
Meanwhile, in County Down, a St Patrick's Day bomb alert took place at St Joseph's Church in Carrickmannon.
More than 100 mass-goers were informed that a device had been found outside the church.
Parish priest Father Anthony McHugh said that he had no doubt the bomb alert was designed to disrupt the St Patrick's Day Mass.
``I had arrived at the church at around 9.30am to prepare for Mass when I discovered the device at the side door,'' Fr McHugh said.
He said it was only through sheer luck he had discovered the device.
``Anyone could have picked this device up,'' he said.
``I dread to think what would have happened then.''
Fr McHugh said that he believed the bombers' intention had been to cause the maximum disruption to the St Patrick's Day Mass at the isolated church.
``I have no doubt this attack was designed to get these people the maximum publicity on St Patrick's Day,'' he said.
``In that aspect I suppose they have achieved their aim.''
Meanwhile, a pipe bomb was discovered in Limavady, County Derry on St Patrick's Day. It was blamed on the unionist paramilitary UVF. It was also believed that the incident was an attempt to disrupt St Patrick's Day celebrations in the town.