Suspected pipe bombs exploded in the flashpoint Ardoyne district where ranks of security forces attempted to hold back nationalist protestors ahead of a hotly disputed Orange Order parade.
Riot squad officers came under a barrage of attack, with rocks and bottles fired at them.
Even though senior republicans urged nationalist youths not to attack police and soldiers, bricks rained down from rooftops.
A car was also set on fire close to police lines where a massive security operation had been put in place for the most contentious of all the July 12 demonstrations taking place across the North.
As tensions heightened a water cannon was used to douse large crowds of nationalists and restore order.
The Sinn Féin president Gerry Adams, who was at the scene along with senior party colleagues in an attempt to keep the situation calm, was among dozens doused by the jets.
But the trouble escalated even before the Orangemen had made their return from Belfast City Centre up along the contentious route past Ardoyne's shop fronts.
A number of explosions occurred as devices were hurled out from the crowd gathered.
One hit a journalist, understood to work for the BBC, in the back.
At least one policeman was seen wounded and had to be taken away by his colleagues.
Earlier, police in riot gear moved in to clear a sit-down Republican protest in North Belfast as thousands of Orangemen took to the streets for the Battle of the Boyne commemoration parade.