Tortilla prices in México continue to rise, with some forecasters predicting an increase of 40 percent by next month, a figure much higher than the 18 percent increase previously announced by the National Chamber for the Tortilla and Dough Industry.

Tortilla prices in México will rise by 18 percent next month, according to Mexico's National Chamber for the Tortilla and Dough Industry.

South American leaders are warning that increased production of biofuels may lead to a surge in food shortages.