The People's Bank of China (PBOC) has required the two lenders to strengthen risk controls and internal management following their involvement in such interbank trades on July 2, it said in a statement.

The two lenders were involved in overnight bond repo trades in the interbank market that put the price at 0.09% on July 2, the PBOC said.

On Monday morning, the overnight repo rate traded at 1.43%.

China Merchants Bank, in a statement to Reuters on Monday afternoon, said that the mistakes in relevant transactions "had gone through friendly negotiations and were corrected based on normal market rates" with its counterparty.

The lender added that it had suspended relevant traders' qualifications based on the central bank's requirements. The bank will "resolutely prevent such risk events from happening again," according to its statement.

Ping An Bank did not immediately reply to a request for comment.

(Reporting by Li Zheng, Andrew Galbraith and Winni Zhou in SHANGHAI, Zhang Shu in SINGAPORE; Editing by Richard Borsuk)