China's securities regulator has punished three companies for price manipulation and insider trading in an effort to protect the interests of retail investors.

The China Securities Regulatory Commission (CSRC) has imposed fines totaling 1.11 million yuan (160,000 U.S. dollars) on three companies in its latest crackdown on illegal market operations.

The commission has always maintained a tough stance against financial market violations with iron fist measures, said Gao Li, a spokesperson for the CSRC.

Thanks to the enhanced crackdown, cases of rat trading, known as front-running in U.S. and European markets, slumped 50 percent year-on-year in the first half of 2018, CSRC data showed.

The Chinese authority has vowed continued efforts to prevent various financial risks and foster a healthy investment environment. The country's two major stock exchanges have released rules to force companies to exit the equity market for serious law violations.