BEIJING -- China's consumer price index (CPI), a main gauge of inflation, grew 2.1 percent year on year in May, down from 2.4 percent in April, the National Bureau of Statistics (NBS) said on Sunday.

The NBS attributed the slow-down in growth mainly to falls in vegetable prices, which shrank 13.8 percent in May from April.

The rise is below the market forecast of around 2.5 percent, according to Wang Jun, analyst with the China Center for International Economic Exchanges, a government think tank.

In May, food prices, which account for nearly one-third of the weighting in China's CPI, increased 3.2 percent year on year, NBS data showed.

On a monthly basis, the CPI in May edged down 0.6 percent from April, compared to a rise of 0.2 percent in April from March.

The data also showed China's producer price index, which measures wholesale inflation, fell 2.9 percent year on year in May, marking the 15th straight month of decline and the steepest drop in seven months, pointing to continued weak market demand.

China aims to hold this year's consumer inflation at around 3.5 percent.