Police officers have used water cannon against rioters after violence broke out in west Belfast.
A crowd gathered in the Forthriver estate off the Ballygomartin Road
A crowd gathered in the Forthriver estate off the Ballygomartin Road and threw bricks, stones and other missiles at the police.
A vehicle was also set on fire in the area.
Earlier, four people were arrested after roads in Belfast were blocked by loyalist protesters causing traffic chaos for the fourth day in a row.
Police cleared many protests off main roads, but were told they faced paramilitary attack if they tried to move women and children protesters.
Earlier, several vehicles were hijacked and set on fire after police carried out searches in a loyalist estate.
One man was arrested during the search operation on the Highfield estate.
Part of the Crumlin Road was closed after a car was hijacked and set on fire and a lorry was set alight on the Ballygomartin Road.
Several vehicles were also set on fire on the West Circular Road.
Public transport company Translink has suspended bus services to Springmartin and Glencairn because of the trouble.
Buses to Ligoniel and Silverstream have been diverted.
Police said they were stepping up operations to deal with loyalist protests causing traffic disruption in parts of Belfast.
They said an operation was in place in the city to keep the main arterial routes at Broadway and the Westlink open and that the Crumlin Road will be kept clear to ensure access to the Mater Hospital.
Assistant Chief Constable Duncan McCausland said all road protests were illegal and that community leaders should exercise their influence to bring them to an end.
He said that the protests, mostly featuring women and children had been peaceful, but that they were causing disruption.
Vehicles have been set on fire in Belfast
"We have always said we would be proactive in dealing with this activity on the streets of Belfast," he said.
There has been trouble, mainly in loyalist areas, sparked by the re-routing of an Orange Order parade on Saturday.
Police and soldiers came under sustained attack over the weekend.
Shots were fired at the security forces as well as blast and petrol bomb attacks in the wake of the Whiterock parade.
A number of vehicles were also hijacked and set on fire.
There were a number of attacks on the police on Tuesday, but not on the scale of the previous three nights.