By Dominic Casciani BBC News Online in Northern Ireland

In the first of two features from Belfast, we report on the tensions in Ardoyne and why few people hold out hope for peace.

 Click here for the second feature from the heart of nationalist Ardoyne.

There are few more obvious signs of sectarian division than the scene that greets you at Ardoyne Road, north Belfast. Irish tricolours fly from lampposts starting at the southern end of the road.

A few yards past an invisible border at Alliance Avenue, the green is replaced by the orange and loyalist flags flutter in the breeze.

Front line: Territory marked out with flags

Ardoyne, an "interface" area where Protestant and a much larger Catholic communities live cheek by jowl, has witnessed some of the worst violence of the Troubles: Mass movements of people, open street fighting, clashes with security forces, shootings and intimidation.

High levels of unemployment persist and this epicentre of the Troubles remains a fertile recruiting ground for paramilitaries.

Along with west Belfast, the north of the city has been the epicentre of killings in the Troubles.

If the peace process must work anywhere in Northern Ireland, it must be seen to work in Ardoyne.

 Click here for a map of the area

But the current violence in north Belfast shows what a long road that peace process still has to travel.

In December last year, Protestant taxi driver Trevor Kell was shot dead near the unofficial line that separates the two communities in Ardoyne.

The following day, loyalist paramilitaries were behind two separate retaliatory shootings, killing one victim, Gary Moore.

This year, loyalists have waged a campaign of pipebombings against Catholic homes.

Some republicans have carried out assaults and intimidation of Protestant women and pensioners using the only local shops and post office.

Matters came to a head in June when loyalists and republicans clashed on Ardoyne Road. Saying that they'd had enough, Protestants blockaded the Catholic Holy Cross Girls' Primary School, ostensibly lying in the Protestant part of Ardoyne. Serious rioting followed and Ardoyne peered over the brink.

Community 'under siege'

Jim Potts, one of the leaders of the school protest, said that his community believed that it was under siege. The blockade had been the only way to get a message across, he insisted.

Jim Potts: "We will not be pushed out"

"People see the pictures of these children but they don't see the attacks that have been carried out against this community," he said.

"We have nothing against the children. But we will not stand by any longer when some people are using the kids as cover for intimidation and attacks.

"We won't allow them to move into our community and push our people out."

Demographic change

The most significant driver of fear is demographic change: The Protestant community has declined in north Belfast as the Catholic community has grown.

Empty homes: Many Protestants have left north Belfast

Twenty years ago, the broader Protestant-unionist population had approximately 20,000 more voters than the Catholic community at general elections.

Today, the numbers are drifting in the nationalist community's favour.

"This is a street-by-street battle for the heart of Ardoyne and therefore north Belfast," said one community worker who wished to remain anonymous.

"The fate of every single house is watched closely. If a Catholic family moved into a home formerly perceived as being Protestant, it would become a front line.

"As the tension increases, the moderates move out and the sense of fear or even invasion increases.

"You couple that with a fragmented Protestant/unionist community here, a great deal of unemployment and a sense that they've got nothing out of the peace process, then things are going to get worse."

There are some loyalists in Ardoyne who now want a "peace line" erected between the communities - gates which can be opened or shut to allow access or keep the communities apart.

But a peace line would inevitably place Holy Cross in the Protestant area and the shops and services on the Catholic side, cementing the divide for good.

Divisions in upper Ardoyne

While the residents group which sprung up at the time of the school blockades has sought to speak for the Protestant community in Ardoyne, it does not have absolute support.

Loyalist paramilitaries: Active in the wings

One resident summed up the feelings of many too afraid to speak publicly.

"Protestants fear the 'greening' of north Belfast and decent people in nationalist Ardoyne should be asking republicans what they think they are going to achieve by doing little to lessen those fears.

"But I have no doubt that if [loyalist paramilitary] UDA elements had not recently arrived in the area from elsewhere, the situation would not have escalated as it did. These paramilitaries are active in this community. To what end, I don't know."

In June, RUC Chief Constable Sir Ronnie Flanagan said he believed the UDA was involved in the clashes following the school protests.

The following month after hundreds of nationalists clashed with security forces, his officers made a similar assessment of republican involvement.

But Jim Potts denies that loyalist paramilitaries are dictating events.

"Paramilitaries are in all communities in Northern Ireland," he said. "I would not tell you that this community does not speak to them at times in the wings.

"What is more important is that this community is able to stand together and say 'no more'."

'Step back and think'

The local Church of Ireland rector, the Reverend Stewart Heaney, has urged the communities to step back and think - though he admits that his hopes of a resolution are based more on faith than anything else.

Rev Stewart Heaney: "Step back and think"

"This has been a very traumatic time for this community, especially with the civil disorder that followed the decisions that were taken to hold protests," said Rev Heaney.

"Let us return to a situation where children can walk to school as they have done for 30 years without protests. At the same time people should travel freely to the shops without any kind of interference.

"What I feel is lacking is a generosity of spirit, a reaching out to each other's side.

"What must it be like for parents who cannot get their children to school? What must it be like for the pensioner who cannot get to the post office?"

In the middle of this fear is a school with some 200 pupils, a lot of people living in fortress homes and flags flying along Ardoyne Road.

And no one is willing to risk what would happen if they took them down.

 Click here to go back

 Click here for the second feature from the heart of nationalist Ardoyne.