Worried that she has said too much, she refuses to give her name, fearing the prescience of her throwaway remark and the implications that could come with it.

For Haiti was yesterday on the verge of civil war.

In the last five days anti-government rebels have taken around a dozen towns around the country in bloody battles that have claimed at least 42 lives. Meanwhile government supporters in Haiti's second largest city, Cap-Haitien, built flaming barricades to keep rebels at bay, according to radio reports.

With the future of the president, Jean Bertrand Aristide, in the balance and little indication of who will replace him, those who have fled the captured towns wait anxiously for news that they can return.

Men with rifles patrol the grounds of human rights organisations.

Rumours of towns fallen and recaptured are born and die in the space of a conversation. With government supporters and rebels both armed and not in uniform it is impossible to know whose side anyone is on.

No wonder, then, that the United Nations yesterday warned of an imminent humanitarian disaster, and academics in the capital were warning of carnage and the potential for massacres.

Outside the tax office, where Emmanuel waits with his typewriter to tap out official-looking letters for the public, there is a nervous calm.

"Everyone knows who is to blame for this situation but many of us are too scared to say," he said.

Even the government admits it does not have control.

"The national police alone cannot re-establish order," the prime minister, Yvon Neptune, said on Monday after the police took back the town of St Marc. Calling the uprising an "act of terrorism", Mr Neptune said the "violence is tied to a coup d'etat".

The government has branded it a coup but its opponents insist it is a popular uprising, rooted in the clampdown on democracy imposed by President Aristide, and the desperate economy over which he presides.

"It's not spontaneous," said Jean-Claude Bajeux, the director of the ecumenical centre for human rights and a staunch opponent of Mr Aristide, referring to the events of the last week. "It's been fermenting for many years. People are fed up with this kind of government and there is a possibility that some of them will get out of control."

Opposition groups date the source of the problem back to the parliamentary elections in 2000, which they claim were rigged in favour of Mr Aristide's party, Famni Lavalas. Unimpressed by the conduct of the ballot many foreign donors withdrew aid, further entrenching the dismal poverty of the western hemisphere's poorest nation.

Now they are demanding that Mr Aristide, whose term does not run out until 2006, resigns immediately. The president has refused to step down but has promised legislative elections - a promise he made last year but has yet to keep.

Efforts at mediation from the Caribbean community, Caricom, and the Organisation of American States, have come to nothing, making the prospect of a bloody conflict between the two sides almost inevitable.

The situation reached a critical point last Thursday when a group calling themselves the Gonaives Resistance Front took over the country's fourth largest city and then paraded the mutilated bodies of the policemen they had killed.

"There could be carnage," said Charles Edouard, a professor at the university in Port-au-Prince. "We are ready for a massacre. But it's the difference between living without power or food or dying to gain power and food. So we have no choice but to continue. We are ready."

At the gate of the faculty of human sciences, Leveille Chanel, 25, carrying Francis Fukayama's book The End of History, said: "We have reached a point of no return. We are not pacifists but we are peaceful people. The president has broken his pact with the people and the people can revoke his presidency."

Students have been at the forefront of the opposition in Port-au-Prince. Alongside human rights activists, business people and some trade unions, their opposition is broad-based but does not reach into many of the capital's slum areas. They are calling for a two-year transitional government followed by elections, but many fear Mr Aristide's departure may be replaced by anarchy.

Haiti has seen more than 30 coups since its independence in 1804.

Mr Aristide was himself deposed in 1991, only to be returned to power with the backing of the United States in 1994.

The political opposition in Port-au-Prince insists it has nothing to do with the armed uprisings elsewhere in the country - a claim the government disputes - but the fighting has clearly strengthened the opposition's hand.

The rebellions have largely been led by former supporters of Mr Aristide, proof, his critics say, that he has been arming his party, which is now turning against him. The government says it the opposition is capitalising on the country's economic plight.

Haiti, which has been ravaged by Aids, is one of the poorest countries in the world, with life expectancy at 53 and 80% of the population living on less than £2 a day.

"Our weakness is economic," said Lesley Voltaire, the minister for Haitians living abroad. "A lot of people are not happy with us because we have not delivered for them."

But Mr Aristide's opponents say the economy is a symptom, not the cause, of the discontent.

"The real coup d'etat started in 2000 when he stole the election," said Mr Bajeux, a former Aristide supporter who was once his minister of culture. "Since then he has had no democratic legitimacy and now the system itself is falling to pieces.

"It's full of political, economic, cultural cracks. It's about to collapse. There is no way to go back."