China's consumer price index accelerated to a three-year high of 6.4 per cent in June, the National Bureau of Statistics said Saturday, increasing the likelihood that monetary policy will be tightened further, dpa reported. The figure was up from May's 5.5 per cent and above the 6.3 per cent analysts had forecast, driven by surging food prices. The increase came even after the central bank raised interest rates three times this year, most recently on Wednesday. The statistics bureau said food prices increased 14.4 per cent in the year through June. Food accounts for more than one-third of an average Chinese person's monthly expenses. Non-food prices rose 3 per cent.