Port au Prince: Hungry Haitians stormed the presidential palace to demand the resignation of President Rene Preval over soaring food prices and United Nations peacekeepers battled rioters with rubber bullets and tear gas.

Rioters were chased away from the presidential palace but, by late afternoon on Tuesday, they had left trails of destruction across Port-au-Prince. Concrete barricades and burned-out cars blocked streets, while windows were smashed and buildings set on fire from the capital's centre up through its densely populated hills.

Outnumbered UN peacekeepers watched as people looted businesses near the presidential palace, not budging from the building's perimeter. Nearby, but out of sight of authorities, another group swarmed a slow-moving car and tried to drag its female driver out the window.

Food prices, which have risen 40 per cent on average since mid-2007, are causing unrest around the world. But nowhere do they pose a greater threat to democracy than in Haiti, one of the world's poorest countries where, in the best of times, most people struggle to fill their bellies.

Fragile socio-economics

"I think we have made progress in stabilising the country, but that progress is extremely fragile, highly reversible, and made even more fragile by the current socio-economic environment," UN envoy Hedi Annabi said on Tuesday after briefing the Security Council.

So bad has the food crisis become that desperate Haitians have come to depend on a traditional hunger palliative of cookies made of dirt, vegetable oil and salt.