Police fired plastic bullet rounds early today to deter at least six youths who breached the security barrier about a quarter of a mile from the Garvaghy Road in Portadown.
The entrance to the road was sealed off for an hour-and-a-half earlier last night, after loyalist protesters paraded illegally for four hours.
Taunting local residents, the band played the British national anthem and played The Sash as they marched around the roundabout on the Dungannon road.
The senior RUC officer in charge, Supt Bertie Carson, said between 8,000 and 10,000 Orangemen from Newtownards, Down, Tyrone and other areas had gathered at the Drumcree field, the largest gathering so far, on the fourth day of the standoff. He said police were gathering video evidence with a view to prosecuting those engaged in illegal protests.
Supt Carson said there were no injuries caused during the incident and no stones were thrown. "The only thing thrown was verbal abuse," he said, adding that the residents' safety was totally secured.
Groups of loyalist youths were still lined along the trench in the field opposite the security forces at 2 a.m. where they had been for many hours beforehand, taunting police and letting off fireworks in their direction.
During the protest Supt Carson spoke to the chairman of the residents' committee, Mr Breandan Mac Cionnaith and Sinn Fein Assembly member, Ms Dara O'Hagan, who had made representations about preventing the Orangemen blocking the road.
Elsewhere, police officers came under attack from gunfire and blast bombs in Newtownabbey, Co Antrim. The shooting started at 10.50 p.m. on the Doagh Road in the loyalist Rathcoole estate, the scene of the most intense disturbances. There were no reports of injuries.
Meanwhile there was an angry reaction to the jostling and verbal abuse of the SDLP deputy leader, Mr Seamus Mallon, after talks with Mr Mac Cionnaith on Tuesday night.
It was a "calculated attempt to make a scene", according to the party's mid-Ulster Assembly member, Ms Brid Rodgers, who had accompanied Mr Mallon. She said those barracking the SDLP did not represent the majority of the nationalist community.