SYDNEY (AFP) - From the rice paddies of Asia to the wheat fields of Australia, the soaring price of food is breaking the budgets of the poor and raising the spectres of hunger and unrest, experts warn. A billion people in Asia are seriously affected by the surging costs of daily staples such as rice and bread, the Director-General of the Asian Development Bank, Rajat Nag, has said. "This includes roughly about 600m people who live on just under a dollar a day, which is the definition of poverty, and another 400m who are just above that borderline," he said. Across Asia, workers made a campaign against high food prices their May Day battle cry last Thursday in marches through cities including the capitals of Indonesia, the Philippines and Thailand. "Once people get hungry they start also getting quite desperate and take desperate measures," Damien Kingsbury of Australia's Deakin University told AFP. Experts blame the high food prices on a confluence of factors, including increased demand from a changing diet in Asia, droughts, the rising use of crops for biofuels, and growing energy and fertiliser costs. In Australia, which usually ranks second after the United States as a global wheat exporter, several years of drought cut harvests to just 13 million tonnes last year from an average of 22 million tonnes. Around the rest of the region, the impact varies from traumatic to minimal: - PAKISTAN: Analysts say public anger over food shortages, particularly wheat flour for the staple roti, was a factor in the defeat of President Pervez Musharraf's allies in elections in February. - AFGHANISTAN: Millions of Afghans are finding it "problematic" to meet their basic food needs with prices of the staple, wheat, doubling in some areas over recent months, the World Food Programme has said. - BANGLADESH: One of the world's poorest nations, Bangladesh has been hit by a doubling in the price of the main staple, rice, in the past year and many low paid workers say they have been forced to make do on only one meal a day. - CHINA: Chinese Premier Wen Jiabao told a meeting of the State Council last month that high prices were the biggest problem in the domestic economy. "The inflation is led by food price rises, which especially hurt the poor," said Ma Qing, a Beijing-based analyst with the CEB monitor group. "So the pressure (on maintaining social stability) is certainly quite large." - INDIA: A general strike against spiralling food prices paralysed Kolkata on April 21 as thousands of police were deployed across West Bengal state to stop protests turning violent. - INDONESIA: Anger over rising food prices was a focus for some 10,000 Indonesians who took to the streets of the capital Jakarta for Labour Day rallies. - JAPAN: In resource-poor Japan, which relies on imports for 60 per cent of its food, companies have hiked prices on everything from beer to beef, mayonnaise and "miso" paste made from fermented soy beans in recent months. - NORTH KOREA: North Korea's food crisis has already seen some people starve to death in remote rural towns, according to an aid group which works in the impoverished communist nation, South Korea's Good Friends organisation. Prices of staple foods have almost tripled over the past year. - SINGAPORE: Singapore is the wealthiest economy in Southeast Asia but charities say inflation is driving more people to join queues for free meals. Consumer price inflation reached 6.6 percent in January-February, officials said. - THAILAND: In Thailand, export and domestic rice prices have risen about 50 percent in a month. Some farmers have taken to arming themselves and staking out their fields at night to protect their precious crop from rice thieves. In a phrase particularly chilling for Asia, the World Food Programme has described rising food prices as a "silent tsunami".