Police arrested three youths during disturbances which followed Saturday's Apprentice Boys parade in Derry.
The parade, the last Loyal Order parade of the year, passed off relatively peacefully with the exception of some sectarian chanting between rival groups of youths at the junction of the Diamond and Ferryquay Street.
Over 2,000 Apprentice Boys took part in the parade, accompanied by 20 bands.
Many city centre shops, which closed during the parade in previous years, remained open on Saturday, though the proprietors reported a quiet trading day. Also, for the first time in several years the police did not erect rows of tall perspex screens which were used to keep rival sectarian groups apart in past years at potential flashpoints along the city centre route.
The disturbances, which were minor, started immediately after the parade had ended when rival groups threw bottles at each other. However, dozens of the 500 police officers on duty quickly moved in and formed a line between the rival factions.
"All in all, we're very satisfied with the way things went today," said Supt John McCarroll, who was in charge of the PSNI operation. "No-one has been hurt, no damage has been caused to premises, most of the shops stayed open and we didn't have to use the perspex screens for the first time in many years to keep rival hoodlums apart.
"There have been three arrests for public order offences and further arrests may follow," he said.