China's "big four" state-owned commercial banks get into full swing, but risks still loom large.

Industrial and Commercial Bank of China, the nation's top lender by assets, reported 164 billion yuan ($25.83 billion) in net profits for the first three quarters, up 28.3 percent from a year ago.

China Construction Bank, the second largest lender, saw its net profits climb 25.8 percent to 139 billion yuan ($21.89 billion) in the January-to-September period.

Bank of China's profits went up 22.1 percent to reach 101.3 billion yuan ($15.95 billion) in the first nine months.

Agricultural Bank of China generated 100.8 billion yuan ($15.87 billion) in net profits, up 43.6 percent in the first three quarters.

"But one cause for concern is the banks' weakening ability to attract deposits due to negative interest rates in real terms," said Qiu Zhicheng, an analyst with the Shenzhen-based Guosen Securities Co. Ltd. "Tightening monetary policies also drained liquidity from the economy."

Bank of China, for example, had 7.97 trillion yuan ($1.26 trillion) deposits at the end of September, representing a decrease of 125.6 billion yuan ($19.78 billion) from June.

"The reduction in deposits will pinch the banks' war chest to extend loans and thus cast an ominous shadow over their growth prospects," added Qiu.

But economists believe risks of financing vehicles of local governments are subdued as the debt burden remains tolerable.

The China Banking Regulatory Commission has recently allowed local governments to delay repayment for some of their debts, reducing the possibility of a debt crisis.

In addition, the Ministry of Finance has launched a pilot program to allow four local governments to issue bonds, which is expected to provide them easier access to capital.