THE PSNI is investigating an illegal loyalist parade in north Belfast on Monday night after riot police were forced to close a section of the Crumlin Road as protesters and bandsmen attempted to walk past the nationalist Ardoyne.
Loyalists have set up a permanent protest camp at the Twaddell interface and have been holding impromptu parades since they were banned from marching the route on July 12.
In recent weeks the protest has escalated.
On Monday evening loyalists attempted to illegally parade along the contested section of the Crumlin Road.
Orangemen in collarettes and a number of loyalists bandsmen were among a group of several hundred protesters who paraded along the Woodvale Road and towards the Ardoyne roundabout.
No permission to parade was applied for making the march illegal.
Officers moved in to form a line of vehicles to block the road, however, around 50 people breached police lines and attempted to parade passed the nationalist interface.
Riot officers used shields to push the crowd back, who managed to get as far as the ambulance station on the Crumlin Road before their efforts were thwarted by police.
There has been an increased police presence in the area since the parade.
A spokesman for the PSNI said they were investigating the incident.
Loyalist protesters have vowed to continue to step up protests at the interface in the coming days and weeks.
PUP spokesman Winston Irvine said loyalists are willing to remain the area for the foreseeable future.
"Those who have been supportive of the three Ligoniel Lodges and the supporting bands decided to vary the parade route on Monday in order to further highlight the repressive determination placed on them by the Parades Commission", he said.
"The feeling I'm getting on the ground is that there is a resolve to continue with the protest and in fact the human rights camp at Twaddell has had widespread support both locally and further afield.
"This is not a short-term approach, there is a 'stickability' that didn't previously exist. People want this issue resolved but are determined to have visible presence in the area until such times as it is."
North Belfast Sinn Fein MLA Caral Ni Chuilin said the parade was "highly provocative."
"The fact that the parade was able to march so close to the Ardoyne interface raises questions about the PSNI response and resources in the area.
"Unionists need to show leadership and use their influence to defuse this tension which is clearly centred in an alliance between the UVF and Orange Order in Belfast."