China's central bank added 70 billion yuan (US$10.3 billion) of liquidity to the nation's banking system this week, after it completed its weekly open market operations Thursday.

The People's Bank of China (PBOC), the central bank, auctioned 13 billion yuan (US$1.91 billion) of three-month bills at an unchanged yield of 1.5704 percent.

The PBOC on Thursday also sold 5 billion yuan (US$735 million) of 91-day repurchase agreements at a yield of 1.57 percent.

The central bank also offered 12 billion yuan (US$1.76 billion) of one-year bills on Tuesday.

Offsetting the 100 billion yuan (US$14.7 billion) of bills and repurchase agreements that matured, the PBOC realized a net cash injection of 70 billion yuan into the money market this week.

Last week, the PBOC took 91 billion yuan (US$13.37 billion) from banks as it tightened liquidity.

In August, the central bank drained 120 billion yuan (US$17.6 billion) from the money market through issuance of bills and repurchase agreements.