The China's central bank on Sunday allowed 40 billion yuan about (6.1 billion US dollars) to drain from the market. 
The People's Bank of China (PBOC) put 70 billion yuan into seven-day reverse repos, a process by which central banks purchase securities from banks with an agreement to sell them back in the future. 
The reverse repos were priced to yield 2.25%, according to a PBOC statement. 
Reverse repos worth 110 billion yuan matured on Sunday, so the central bank has effectively drained 40 billion yuan from the market, according to China's (Xinhua) News Agency. 
On Sunday's interbank market, the benchmark overnight Shanghai Interbank Offered Rate (Shibor) was 2%.