BEIJING, Jan. 21 -- The People's Bank of China, the country's central bank, announced on Tuesday it has injected 255 billion yuan (41.76 billion U.S. dollars) into the money market through open market operations.

It is the first cash injection by the central bank through reverse repurchase agreement (repo) operations this year. The central bank had stopped such operations for four straight weeks.

The central bank's last reverse repo operation, which came on Dec. 24, released liquidity worth 29 billion yuan to the money market.

The yield for seven-day reverse repo stood at 4.1 percent, while that for three-week reverse repo was 4.7 percent, according to the central bank.

The liquidity injection came as interbank bond repurchase rates climbed. Rates for overnight and seven-day products both rose sharply on Monday to 4.3 percent and 6.6 percent respectively.

Meanwhile, the Shanghai Interbank Offered Rate (Shibor), a gauge of interbank borrowing costs, also gained sharply on Monday, with the overnight Shibor rising 107.1 basis points to 3.89 percent, and the seven day and two week rates gaining 155.3 points and 80.3 points respectively to hit 6.33 percent and 5.54 percent.

Zhong Zhengsheng, an analyst at Everbright Securities, said that the central bank move aims to ease liquidity pressure that builds up ahead of the Spring Festival, the most important Chinese traditional festival that falls on Jan. 31 this year.