China's central bank said Tuesday that it would give more prominence to stabilizing the overall price levels to keep the financial system secure and stable.

In a report posted on its website, the People's Bank of China (PBOC) said China's monetary policy should be in line with the principles of "generally prudent," "measured adjustments" and "optimized structure."

The statement came hours after the PBOC raised banks' required reserve ratios (RRR) on Tuesday for the ninth time since October, and the sixth this year, to try to curb inflation.

Earlier on Tuesday, the National Bureau of Statistics announced that China's consumer inflation in May, largely fuelled by high food prices, rose in May to 5.5 percent, a 34-month high.

The 50 basis-point increase in the RRR means that big banks have to put aside 21.5 percent of their deposits, a record high, locking up funds that could otherwise be loaned out.

In addition to tightening bank reserve requirements, China's central bank has lifted interest rates four times since October to quell inflation.

"The Chinese economy is suffering some long-term and short-term problems that are interweaved, and co-existing systemic and structural problems," said the central bank.

China's macro-economic regulation is faced with a number of challenges including the risk of asset price bubbles, rising inflationary pressure, and the need to accelerate the economic restructuring, according to the statement.

The PBOC said the rising inflationary pressure was a result of a mix of cyclical and structural factors, which included the extremely loose monetary policies adopted in some major developed economies.

"The loose global monetary conditions have pushed up inflation expectations and the prices of commodities which thus exacerbated China's imported inflationary pressure," said the statement.

The central bank also attributed the rising inflationary pressure to excess liquidity, increases in prices of agricultural products as a result of bad weather conditions, and rising labor costs.