BEIJING, Aug. 16 (Xinhua) -- China's top economic planner on Thursday determined that the China branch of the International Ramen Manufacturers Association (IRMA) has illegally fixed prices for instant noodles.

The IRMA branch had held three meetings of instant noodle manufacturers and related businesses early this year to discuss specific plans to raise prices, said the National Development and Reform Commission (NDRC).

This constituted collusion and manipulation of the market in violation of the Price Law.

The branch had published a meeting memo and caused panic buying in some cities, which seriously disrupted market order, said the NDRC.

The NDRC has ordered the branch to make a public explanation and invalidate the illegal pricing agreement.

The NDRC is continuing its investigation into the branch.

Ramen prices of major manufacturers, who hold 95 percent of the market share, jumped 20 percent on average and some rose up to 40 percent in July.

The low-end instant noodles cost only one yuan (13 U.S. cents) per packet before the price change.