The Haitian Senate has fired the impoverished country's prime minister after a week of violent food riots and ignored an emergency plan announced by President Rene Preval to slash the cost of rice.

Sixteen of 17 senators who attended a special session of the chamber voted against Prime Minister Jacques Edouard Alexis, who was inaugurated in June 2006 along with a coalition cabinet meant to unite the fractious Caribbean nation of nearly nine million people.

"Now it's my turn to play," Mr Preval says when he was told by journalists of the Senate vote against his ally.

The vote came shortly after he and leaders of the private sector had revealed an emergency plan to cut the cost of a sack of rice to $US43 ($A46.20) from $US51 ($A54.80).

New govt to be chosen

Dealt what political analysts consider a serious blow by the Senate vote but not a crushing one, Mr Preval says he would be getting in touch with Senate leaders and legislators from the lower house to pick a new government.

The clash with senators came after days of rioting over food prices in which at least five people were killed.

Crowds of stone-throwing Haitians began battling UN peacekeepers and Haitian police in the south of the country on April 2, enraged at the soaring cost of rice, beans, bread, cooking oil and other staples.

The unrest spread to the capital Port-au-Prince this week, bringing the sprawling and chaotic city to a halt as mobs took over the streets, smashing windows, looting shops and setting fire to cars.

Businesses, donors to pay

Mr Preval, whose appeal on Wednesday for an end to the violence brought a tense calm to the capital, said $3 of the cut in the price of would be paid by businesses. The rest would be funded by international donors.

"The situation is difficult everywhere around the world, everyone has to make a sacrifice," he told a news conference on Saturday in the opulent National Palace in downtown Port-au-Prince.

"We are not going to lower taxes on food ...," he says, reiterating that the poorest country in the Americas could not afford to cut its revenues or it would not have enough money to pay for longer term projects that create jobs and boost agriculture.

Food costs have soared worldwide because of a combination of surging demand in emerging countries such as China, competition with biofuels, high oil prices and market speculation. Disturbances have broken out in a host of poor nations, primarily in Africa.