The central bank also appears to be withdrawing liquidity via a reduction in reverse repos, a mechanism to increase or decrease the money supply in the banking system. For at least three days in a row, the People's Bank of China did not conduct any reverse repo operations—causing 58 billion yuan ($9.5 billion) to be removed from the system this week, on top of 45 billion last week, according to Chinese media.
The moves may be in response to recent inflation and housing-price data which have shown increases despite the central government's attempts to slow down both, especially the housing market.
(Read more: Shanghai shares fall to lowest in a month)
In a related event announced on Friday, China has launched a benchmark lending rate for the first time. Reports indicate that it will be used to guide commercial banks on what rate to set—something Chinese bankers aren't accustomed to doing, because up until very recently lending rates have been controlled by the central government, not the market.
"Leaders in Beijing have repeatedly signaled that they are serious about fundamental economic policy reforms in 2013, including interest rate reform," said Dan Rosen of Rhodium Group. "They are now implementing those commitments."
So far however, the government still controls deposit rates—a key factor in what seem to be ever-rising real estate prices.
The government imposes a ceiling on the interest rates that banks are allowed to pay depositors; currently, it's capped below the rate of inflation and as a result, depositors are tempted to seek higher returns elsewhere—such as in real estate.
—By CNBC's Michelle Caruso-Cabrera. Follow her on Twitter @MCaruso_Cabrera.