Twelve men and a 15-year-old juvenile were arrested following street disturbances during and after Saturday's Apprentice Boys parade in Derry.
Nationalist youths, many wearing Celtic T-shirts, threw stones and bottles at police after the screening in pubs of the match between Rangers and Celtic, which coincided with the Apprentice Boys "shutting of the gates" ceremony in the centre of Derry.
As about 2,000 members of the Loyal Order were parading through the city centre, a crowd of about 100 youths, many of whom had been drinking in city centre pubs, threw stones and bottles at police officers.
The Apprentice Boys were holding their annual parade to celebrate the start of the Siege of Derry in 1688, when 13 apprentices closed the gates to deny the Jacobite army of King James II entry to the city.
The high point of the traditional parade is when the Apprentice Boys set fire to an effigy of Lundy, the governor of Derry at the start of the siege, who was ousted when he wanted to welcome the Catholic army of King James.
As the Apprentice Boys paraded to set fire to the effigy on Saturday afternoon, they and the police were attacked.
Dozens of police reinforcements were rushed to the junction of Bridge Street and Carlisle Road where the nationalist crowd were throwing missiles both at the marchers and at lines of PSNI officers.
As the intensity of the attack increased, the police forced the crowd down into Foyle Street. Several shoppers were caught up as the officers, all in riot gear and carrying shields, forced the crowd of nationalists away from the loyalist parade.
Following a 30-minute stand- off, the nationalist crowd then moved into Shipquay Street where they again threw beer-bottles and stones at police officers and police Land-Rovers.
As the disturbances continued, the Apprentice Boys continued to parade less than 50 yards from scene of the trouble.
While dozens of police cameramen filmed and photographed the disturbances, dozens of youths continued to run towards police lines to throw beer bottles or stones.
After an hour-long stand-off, the police advanced down Shipquay Street, again making several arrests. Further trouble flared up at nearby Castle Gate, but the police quickly sealed off the area, which is a gateway between the city centre and Waterloo Street.
Mr William Allen, the governor of the Apprentice Boys, later described the violence as both needless and unnecessary. "What has it achieved - nothing," he said.
"It was unfortunate that our celebration today clashed with the Rangers-Celtic game, but our culture is more important to us than any football game.
"I'm saddened that some people feel that for some reason they have to have a go at us, but you'll always get your minority of trouble-makers everywhere."
Meanwhile, a senior PSNI officer said further arrests were expected in addition to the 13.
"Our job today was one protecting the public and protecting property. We have achieved that objective, but unfortunately many people, no doubt some of them fuelled by alcohol, have acted in an unlawful manner. Seven [of the 13\] have been charged with disorderly behaviour.
"They have been released on police bail to appear in court on December 30th. Two other men have been charged with riotous behaviour and one other with attempting to hijack a vehicle," the PSNI officer said.
One of those who witnessed the police operation was Mr Tom Constantine, the Police Oversight Commissioner, who was appointed by the British and Irish governments to ensure the full implementation of the Patten Report.