KEY POINTS:
Governments worldwide are restricting exports of staple foods to protect supplies amid protests from both the public and farmers.
Protests in Haiti against the rising cost of food have themselves come at a high price, with at least five people killed and 200 injured.
During the last year the price of dietary staples have rocketed, including wheat, rice and soy, which in some cases have more than doubled. The United Nations Food and Agriculture Organisation said global grain stocks were at the lowest level since the 1980s.
The protests in Haiti cost Prime Minister Jacques-Edouard Alexis his job, and unrest has hit other countries including Egypt, Indonesia, Mozambique, Senegal and Bangladesh - where a 10,000 strong protest was broken up by police using teargas.
World Bank President Robert Zoellick this month told a Washington meeting of the G7 wealthiest countries that the world was facing a tragedy.
The World Food Programme asked developed countries to provide US$500 million ($635 million) by May 1.
The reason for soaring food prices included the transfer of land previously used for food production to crops for biofuel, poor harvests, rising wealth and demand among developing countries, increased fuel costs and speculation on futures markets.
Faced with rising costs and possible shortages, many countries have taken action to protect local populations by restricting or banning exports.
India banned the export of non-basmati rice last year, leading to protests from farmers. China, Egypt and Vietnam have banned rice exports until June. Cambodia introduced a two-month ban on rice exports in March, which has now been partially lifted while Indonesia has cut exports of medium-grade rice.
Russia and Kazakhstan have introduced export tariffs on wheat, with restrictions also imposed by Ukraine.
Argentina has increased export tariffs on soybean and sunflower seeds, leading to a strike by farmers.
British Prime Minister Gordon Brown said the problem of increasing hunger needed a co-ordinated international response, including by the World Bank, International Monetary Fund and the UN.
Brown wanted an examination of the impact of biofuel production in developing countries to be raised and more effort put into achieving a global trade deal at Doha.
