Palestinian refugees carry food aid they received from the United Nations Relief and Works Agency for Palestine Refugees (UNRWA) in Rafah, southern Gaza on April 24, 2008. The U.N. agency for Palestinian refugees has warned that aid distribution will end in the Gaza unless Israel allows new fuel supplies to Gaza. (UPI Photo/Ismael Mohamad)

UNITED NATIONS, April 27 (UPI) -- The rise in worldwide food prices left traders in Chicago scrambling to keep up with orders and Egyptians rioting for bread, economists say.

Economists say a severe drought in Australia and the increased planting of corn for biofuels instead of wheat for food on U.S. farms caused much of the inflationary effect, The Washington Post (NYSE:WPO) said Sunday.

The prices have had a ripple effect on world markets, sparking riots in Egypt and forcing the prime minister from office in Haiti. The United Nations says average consumers may soon feel the effects of the 80 percent rise in global food prices since 2005.

"This crisis could result in a cascade of others ... and become a multidimensional problem affecting economic growth, social progress and even political security around the world," U.N. Secretary Ban Ki-Moon' title='General Ban Ki-Moon' class='tpstyle'>General Ban Ki-Moon said.

The collapse of the Soviet Union ushered in an era of global economic integration, the Post said, but the same factors that brought a global equilibrium to manufactured goods are absent in the government subsidized food market.

But some European leaders began to sound warnings of the market influence over human necessities.

"We must not leave the vital issue of feeding people to the mercy of market laws and international speculation," said French Agriculture Minister Michel Barnier.