IN the city centre, no one would think the peace process is hanging by a thread. Shoppers go in and out of stores in their droves. Young men harangue the crowds to buy the Big Issues.

Schoolgirls sit giggling in the grounds of City Hall. Copies hand in hand linger at the windows of jewellery shops. Belfast might be awaiting further IRA attacks or a renewal of loyalist violence but, in the big stores, there is no obvious extra security.

The tall uniformed men aren't back checking bags or scrutinising customers for potential bombers. Cars still have free access to the city centre.

Ms Annette Thompson, from east Belfast, said she was terrified of another IRA attack but didn't want a return to high security. "I'm glad the town isn't behind barricades again," she said. "That's what the IRA wants. We should live a normal life for as long as possible.

"I suppose if there is another bomb, things will have to change. But in the meantime we mustn't let the terrorists get us down." Many shoppers said they knew the situation was precarious but refused to believe the worst.

"After two years of peace here, I couldn't stand a return to violence," said Ms Clare Murphy, from south Belfast. "It would be terrible for our children. I don't even want to think about it. I'm just hoping that there won't be any more bombings or shootings."

The chief executive of the North's Chamber of Trade, Mr Frank Caddy, said he hoped common sense would prevail among politicians and paramilitaries.

The end of the IRA's de facto ceasefire in the North on Monday has already caused a slight downturn in business in the city centre. "The most notable drop has been in the number of southerners crossing the Border to shop," Mr Caddy said.

"Anyone considering further violence should catch themselves on. It would be disastrous. We would lose out on jobs, investment and tourism. It would be awful at Christmas. Who would feel like celebrating under those conditions?"

Traders had decided against a return to heavy security as they didn't want to spoil the relaxed ambience of the past two years.

"Crude security measures haven't been reintroduced," Mr Caddy said. However, the stores were conscious that there was now an extra need to be careful. People mightn't see the measures taken but they were there. "Closed circuit television has been installed in the city centre and there is a radio link between stores."

In the streets of north Belfast, apprehension about the volatile situation is almost palpable.

The geography of the place makes it more dangerous than other areas of the city. There are dozens of interface points where Catholic and Protestant streets meet.

A 10 ft metal fence was erected at Halliday's Road on Monday to separate the loyalists of Tiger's Bay from the nationalists of the New Lodge. There were serious sectarian clashes in the area during the summer.

A nationalist woman said she was delighted with the new security. "After the IRA attack on Monday, we are just waiting for the loyalists to strike. Everyone is very, very frightened, but we wouldn't even be able to sleep in our beds if the fence wasn't there."

Dr Brian Feeney of the SDLP said fear was widespread among Catholics. "The media might speculate that the loyalists will attack Dublin, but there is a real feeling here that whatever happens will happen in north Belfast. It bore the brunt of things during the Dr Feeney said that, despite the peace process, nationalists in the area had continued to suffer sectarian assaults. A young tennis player, Garth Parker, had been beaten to death in June and there was a catalogue of other violence.

"Dozens of Catholics were forced out of their homes during the Drumcree standoff," he said. "Over £1 million worth of damage has been caused by arson attacks on Catholic schools in the area over recent months.

"The UDA set a shop assistant on fire in Duncairn Gardens. There have been nightly attacks on people's homes by loyalists. Bricks and ball bearings have been fired through windows. The RUC has pretended that many of these incidents were not sectarian. They have been deliberately downplayed.

"If the IRA had been responsible for such a huge amount of violence against Protestants, it would have been raised in the United Nations. The fear among Catholics is that they will be facing loyalist bullets now, too."

However, Mr Nigel Dodds of the DUP said it was totally wrong to portray Protestants as the aggressors and Catholics as the victims. "There have been many cases of Protestants being attacked and intimidated," he said.

"Ordinary decent Protestants are sitting in their homes feeling very afraid. There had been previous bombs in England but there was a feeling that the de facto IRA ceasefire in Northern Ireland would continue and nothing would happen here.

"Protestants are in limbo at the moment. They are just listening to the radio or television, awaiting news of the next attack. They feel that there are people on the nationalist side whom nobody controls."

A PROTESTANT woman in Tiger's Bay said loyalists believed it was only a matter of time before there was a "Provo massacre". IRA gunmen had been itching to kill loyalists since the ceasefire was announced and had now been given free rein by their leaders, she said.

"It's the young people I feel sorry for," she added. "Mothers are going to be terrified every time their children go out. I thought we had left those days behind us but the Provos haven't changed. There will never be peace in Northern Ireland."

In west Belfast, people are venting their anger at the RUC and British army, not the IRA. There has been a heavy security presence in the area since Monday's bombing. Dozens of roadblocks have been set up.

Motorists allege that police are "punishing" them for the attack. "They can't get the bombers so they're taking it out on us," one driver said.

"They are hammering us for things they would normally turn a blind eye to a light not working or a dodgy tyre. They are demanding that driving licences are produced at police stations within five days. They have gone totally overboard."

A Catholic house on the loyalist Black's Road was stoned and petrol bombed on the night after the Lisburn bomb. "Nobody knows what will happen next," said a woman waiting for a black taxi in the Falls.