BEIJING, Feb. 17 -- China's top economic planner said Friday it would stockpile 20,000 tons of frozen pork to replenish state reserves, as an index monitoring pork prices has dropped below the warning level.

The index, the national average of pork prices against grain prices, has fallen below the warning level of 5 to 1, said the National Development and Reform Commission.

According to a work plan for stabilizing the pork market, China has introduced a three-level early-warning system to raise the alarm for excessive ups and downs in hog prices.

The commission said it would work with relevant departments to start this year's first stockpiling work for state pork reserves and guide local governments to purchase pork.

China pays close attention to price changes in the pork market and will continue to strengthen the regulation of production capacity and price to keep the market stable.