A severe winter drought is threatening crop production in China, the world’s biggest wheat provider, the UN’s Food and Agriculture Organisation said.

Substantially below-normal rainfall since October in Northern China has not only put the crop at risk but has also caused shortages in drinking water, affecting over 2.57 million people and their livestock, FAO said.

“The ongoing drought is potentially a very serious problem,” the Rome-based agency’s alert said, adding that the main affected provinces – around 5.16 million hectres – represent two-thirds of national wheat production.

On Monday, the FAO warned that floods and heavy rain across southern Africa have damaged thousands of hectares of farmland, raising fears for food supplies.

World food prices reached their highest level ever recorded in January and are set to keep rising for months, the agency said last week, warning that the hardest-hit countries could face turmoil.

Rising food prices have been cited among the driving forces behind recent popular revolts in North Africa, including the uprising in Egypt and the ouster of Tunisia’s president Zine El Abidine Ben Ali after a 23-year rule.

And in its latest survey, FAO said its index which monitors monthly price changes for a variety of staples averaged 231 points in January – the highest level since records began in 1990.