TOKYO -- Japanese government-stockpiled rice released through no-bid contracts with retailers has hit store shelves in the country, amid high prices of other types of rice.

Some retailers, including major supermarket operator Ito-Yokado, began selling the grain at some of their outlets on Saturday, with a price tag of 2,160 yen ($15) including tax for a 5-kg bag.

At Ito-Yokado's Omori store in Tokyo's Ota Ward, 500 5-kg bags of reserve rice sold out in just 30 minutes after the store opened. Other Ito-Yokado stores will also start selling reserve rice on Sunday or later.

In the latest effort to bring down surging rice prices, the Japanese government offered the sale of a total of 300,000 tons of its stockpiles directly to retailers earlier this week.

The agriculture ministry initially offered government-stockpiled rice through auctions. But it switched to selling it directly to retailers, bypassing auctions that have prevented government control over prices.

According to government data, the average price of rice sold at Japanese supermarkets reached a record 4,268 yen ($30) per 5 kg in early May, roughly double last year's level.