ROME - World rice prices that have tripled in Asia over the course of the year may decline, but overall food prices will remain high for years to come, leaving millions more hungry, a U.N. food agency warned yesterday.

High oil prices, growing demand, flawed trade policies, panic buying, and speculation have sent food prices soaring worldwide, triggering protests from Africa to Asia and raising fears that millions more will suffer malnutrition.

Yesterday, tens of thousands of workers in Senegal - including teachers, tax officials, fishery and port workers - stayed home as part of a strike staged by unions to protest the spiraling cost of rice, fuel, and other basic goods.

Surging food prices also have sparked riots in Haiti and fed worries about supplies in the Philippines.

The Food and Agriculture Organization said it had some good news: The world prices of most agriculture commodities have started to drop.

The bad news: The prices are unlikely to fall back to pre-2007 levels, the agency said in a report yesterday.

"We are facing the risk that the number of hungry will increase by many more millions of people," said Hafez Ghanem, assistant director-general of the FAO.

Conditions on the global rice market could ease as new crops are harvested around the world. But price pressures will remain high until at least October or November, when the bulk of this year's paddy crops reach the market, the report said.

"Stock levels are low, and you need several good seasons to replenish them," Ghanem said. "There will be some improvement, but we don't expect a major change."

Internationally, rice prices skyrocketed about 76 percent from December to April while overall food prices have risen 83 percent in three years, according to the World Bank.

The FAO said the price pressure could ease further if producing countries such as India relaxed export restrictions on rice.

Recent natural disasters such as the cyclone in Myanmar and the earthquake in China are likely to have a domestic impact, rather than on international markets, FAO experts said.