* Change to a subsidy scheme left some without ration
* Protests small but evidence of anger over living costs
* Government says issue will be resolved within 48 hours (Adds minister of supply comments)
By Haitham El Sheikh and Ahmed Abd Elkawey
ALEXANDRIA, Egypt, March 7 (Reuters) - Hundreds of Egyptians protested around the country on Tuesday, blocking roads and surrounding government offices, after a change to the way bread rations are managed raised fears that the government was cutting food subsidies by the back door.
Bread subsidies are an explosive issue in Egypt, where more than 70 million people receive state rations.
Core inflation in the country has soared above 30 percent since Egypt floated its currency in November, securing a $12 billion loan package from the International Monetary Fund to support a government austerity programme.
Protests began on Monday after changes to a bread subsidy scheme left some people without their ration.
Unrest grew on Tuesday, with angry crowds gathering in the port city of Alexandria, in at least one poor Cairo neighbourhood, and several other cities across Egypt.
Supply_Uprising became the top trending Twitter hashtag for Egypt as Egyptians posted pictures of confused people outside bakeries and in the street. The government sought to reassure Egyptians the issue would be resolved in days.
"We were surprised when the bakers refused to give us bread with the excuse that the Supply Ministry reduced their rations," said Ahmed Faraj, an Alexandria resident.
Most protests drew small crowds and dissipated quickly, but offered the first major evidence of public anger over rising living costs.
"We are suffering from high prices. We have nothing left to live on but bread and now the government wants to deprive us of it," said Samia Darwish, a 50-year-old homemaker in Alexandria.
The dangers are not lost on President Abdel Fattah al-Sisi, in a country where economic discontent has helped unseat two presidents in five years. He has promised prosperity and stability in the aftermath of the 2011 Arab Spring uprising, and has committed to protecting the poorest from the pain of austerity.
"We want the president to know that the poor are dying of the high prices," said Gamal Ahmed, from Alexandria.
Egypt operates a system in which each family receives a plastic card to buy five subsidised loaves per person per day. The government then pays bakeries a subsidy per loaf.
Bakers also receive "gold cards" to sell bread to individuals without a smart card – generally those waiting for cards who have been issued temporary paper cards in the mean time.
The Supply Ministry on Monday denied it planned to cut bread subsidies after local media reported that rations would go from five to three loaves a day.
However, last week it did reduce the amount bakers can sell via the "gold card" scheme. The move is likely aimed at reducing misuse of those cards, which costs the government hundreds of millions of pounds a year.
Supply Minister Ali Moselhy told a news conference that citizens would not see their bread rations reduced as temporary paper cards are phased out and replaced by smart cards.
"Apologies to all citizens that have not received loaves of bread. Rest assured that this issue will be resolved within 48 hours ... Every citizen has a right to bread," he said.
A Reuters report last year revealed flaws in the system allow bakers to overstate sales to profit from the black market, where they sell subsidised flour to private bakeries at a profit, costing the government billions of pounds.
Abdel Aal Darwish, the head of the bakeries division at the Alexandria Chambers of Commerce, called on the government to reverse the move and issue all Egyptians with cards. (Additional reporting by Ahmed Aboulenein, Ali Abdelaty, and Eric Knecht in Cairo, Writing by Lin Noueihed; Editing by Julia Glover and Alison Williams)