The United Nations will set up a top-level task force to tackle the global food crisis in an attempt to avert what it calls “social unrest on an unprecedented scale”, Ban Ki Moon, the Secretary-General, said yesterday.

The first priority of the task force would be meeting the $755 million shortfall in funding for the World Food Programme.

“Without full funding of these emergency requirements, we risk again the spectre of widespread hunger, malnutrition and social unrest on an unprecedented scale,” the Secretary-General said after a meeting of UN agency heads in Berne, Switzerland.

The move came as Robert Zoellick, the head of the World Bank, strongly criticised the bans on rice exports that have been imposed by several countries, including Vietnam and India. He said that they had made worse the problem of high food prices.

Thailand was forced to open its state rice stockpiles yesterday in an attempt to cool the market for the grain.

The Thai Government, in a move that triggered an immediate 4 per cent drop in local cash prices for rice, said that it would release 2.1million tons of reserves on to its domestic markets.

Thai officials forecast further price falls as the imminent harvest hits the market and Asian nations rush to plant more.

Nevertheless, traders are braced for future price rises as Asian farmers prepare for what could be the most closely scrutinised rice planting for more than four decades.

With global sensitivity to rice prices at high level, the potential impact of a typhoon or late monsoon has increased.

Although the imminent Asian rice harvest is expected to ease short-term panic and to cause rice prices to fall from a record of almost $25 (£12.67) per 100lb, commodities traders say that the once-stable rice futures contract has gained an unprecedented vulnerability to political and meteorological news.

Kenji Kobayashi, a grains trader at Kanetsu Asset Management, in Tokyo, said that any bad or unexpected weather around this year's second rice planting in late May could push rice prices 20 per cent higher to $30.

The alert comes as governments worldwide are awaking to what rice experts say is a long-term neglect of the fragile economics of rice production.

Nations such as the Philippines - self-sufficient in rice 30 years ago - are now big importers and have been key drivers of the record price surges in their scramble to buy supplies.

Countries that decided to underinvest in feeding themselves face hardship and unrest as rice exports are stopped by traditional suppliers such as Vietnam, India and China.

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