BEIJING -- China's central bank announced Thursday that it has conducted "outright reverse repo" operations, the first of its kind since the monetary policy tool was introduced earlier this week.

In a statement, the People's Bank of China said it carried out the operations in the amount of 500 billion yuan (about $70.2 billion) through a variable-rate tender with a fixed quantity and multi-price auction, with a tenor of six months.

The move was aimed at keeping liquidity in the banking system adequate at a reasonable level, according to the central bank.

On Monday, the central bank unveiled the instrument of outright reverse repo operations on the open market to enrich its monetary policy toolkit.