World Bank President Robert Zoellick and British Prime Minister Gordon Brown have said the issue of skyrocketing food prices needs to be front and centre at the highest political level in every country, and Brown said he would raise it at meetings of the Group of Eight powerful nations.

Concerns about rising food costs took on new urgency as senators in Haiti ousted Prime Minister Jacques Edouard Alexis after a week of food-related rioting in which at least five people were killed. There have also been protests in Cameroon, Niger and Burkina Faso in Arica, and in Indonesia and the Philippines.

In just two months, rice prices have closed in on historic highs, rising by around 75 percent globally and by even more in some markets. Meanwhile, the cost of wheat has climbed by 120 percent over the past year, more than doubling the price of a loaf of bread in most poor countries, the World Bank said.

The problem is most worrying in developing countries where food represents a larger share of what poorer consumers buy. It threatens to sharply increase malnutrition and hunger, while reversing progress in reducing poverty and debt burdens among the poorest nations.

Top development officials who gathered on Sunday for a meeting of the International Monetary Fund and World Bank's joint Development Committee also called for action to address climate change. They urged the World Bank to mobilize financing to help the poorest nations deal with threats from global warming.

Indian Finance Minister Palaniappan Chidambaram said rising food and energy costs threatened to stir more social unrest.

"It is becoming starker by the day that unless we act fast for a global consensus on the price spiral, the social unrest induced by food prices in several countries will conflagrate into a global contagion, leaving no country -- developed or otherwise -- unscathed," he said.

"The global community must collectively deliberate on immediate steps to reverse the unconscionable increases in the price of food, which threatens to negate the benefits to the poor nations from aid, trade and debt relief," he said.

His concerns also reflect worry about the impact higher food prices are having on overall inflation in India, which hit its highest level in more than three years in late March.

Douglas Alexander, Britain's minister for international development, said his country is willing to work with others to bring prices down. "Much has been said this week about rising food prices, but now is the time for urgent action to tackle the crisis, which is affecting millions of the poorest people across the globe," he said.

Alexander also pointed to higher fuel costs and said it was important that global oil supplies "are sufficient to ensure the market has flexibility to respond to potential supply shocks and changes in demand."

The World Bank has warned that the rise in food prices is not a temporary phenomenon and has said prices are likely to remain elevated this year and next before moving lower, and that they will likely remain above 2004 levels through 2015.

One of the biggest factors behind the sharp rise in food prices is the increased use of crops for biofuels as an alternative energy source. Almost all of the increase in global corn production from 2004 to 2007 went to biofuels in the United States, where farmers are heavily subsidized.

Other factors that have contributed to the food-price surge are the growth in demand in Asia as that region grew wealthier, droughts in Australia and the rising cost of fertilizers.