A mob of up to 200 loyalists disrupted a Catholic church service at a cemetery on the outskirts of Belfast on Sunday afternoon and later threw bricks and stones at service-goers.
Loyalist youths later hijacked two vehicles and set them alight at Doonbeg Drive in the nearby Rathcoole Estate.
The attack followed death threats against Father Dan White, parish priest of St Mary's on the Hill church in Glengormley, who conducted the service.
Father White said he had been warned by police late last week of death threats against him.
``I think what we've had was a disgraceful exhibition of bigotry and anti-Catholic prejudice,'' he said.
``I think that's something that's always simmering under the surface in our society, but unfortunately we saw it and we heard it today in all its repugnance.''
The `Cemetery Sunday' service was previously the victim of a loyalist bomb attack in June 2001.
Trouble was feared at the service after Catholic graves were damaged in the cemetery earlier this week. Five Celtic cross tombstones were broken or knocked down when vandals attacked graves early on Monday.
Then on Friday, graffiti was daubed on the doors of the Catholic church. Tthe letters KAT -- an abbreviation for the loyalist slogan `kill all taigs [Catholics]' -- was painted on the main entrance to the church.
More than 20 memorials at Catholic graves in the cemetery were vandalised in June. Crosses were smashed and headstones overturned in an attack blamed on loyalists.
The cemetery is beside Rathcoole estate, a housing estate where Catholic postman Daniel McColgan (20) was murdered by loyalist paramilitaries of the Ulster Defence Association as he arrived for work in January 2002. His grave in Carnmoney was damaged in a similar attack the following May.
The attacks were the final straw for a father-of-three.
The man said the latest desecration of his wife's grave had compounded his grief and that of his 12-year-old son and nine-year-old twins.
``I'm thinking of taking her out of Carnmoney. I can't go on like this,'' said the man, who does not want to be identified.
After assessing the damage the widower broke the news to his children who lost their mother to breast cancer in 1999.
``My wife's sister came to pay her respects and found the gravestone vandalised. If she hadn't of come down, I wouldn't have been told,'' he said.
``I am absolutely devastated. It's been hard enough getting over my wife's death, but to come down and see this desecration.
``They're just vandals, bigoted and full of hatred. There is no doubt this was sectarian.
``They know if there is a Celtic cross a Catholic is probably buried there.''
Mass at a nearby Catholic church in Limavady was also cancelled.
There were also renewed sectarian attacks on Catholic homes in Deerpark in north Belfast; while eight graves were also desecrated at a Catholic cemetery near Scarva, County Down.