London, March 27 : Rocketing global food prices as a result of the war in Ukraine could trigger riots from those going hungry in poor countries, the head of the World Trade Organization has said. Ngozi Okonjo-Iweala warned food-producing countries against hoarding supplies and said it was vital to avoid a repeat of the Covid-19 pandemic, when rich countries were able to secure for themselves the bulk of vaccines, reports the Guardian. In an interview with the Guardian, the WTO director general expressed concern about the knock-on effects of Russia's invasion Â? stressing the dependence of many African countries on food supplies from the Black Sea region. "I think we should be very worried. The impact on food prices and hunger this year and next could be substantial. Food and energy are the two biggest items in the consumption baskets of poor people all over the world," Okonjo-Iweala said. "It is poor countries and poor people within poor countries that will suffer the most." Okonjo-Iweala, a former Nigerian finance minister, said 35 African countries were dependent on food imported from the Black Sea region, adding that Russia and Ukraine were responsible for 24 per cent of global supplies of wheat. /IANS