The head of Northern Ireland's police force has condemned leaders of the Orange Order for inciting protests in Belfast that left more than 30 officers injured.

Loyalists rioted overnight after they were banned from marching in the Republican Ardoyne area.

The violence has been described as "shameful and disgraceful" by police.

Four hundred extra police from across Britain are being sent to Northern Ireland. More than 600 officers were already in the region supporting the PSNI operation as Orange Order protests over the contested parade routes spiraled into violence in North Belfast.

The DUP's Nelson McCausland blames the Parades Commission's decision to reject the route.