China's stock exchanges, securities brokers and funds should educate investors about the risks of stock market investments amid an 81 percent surge in the nation's benchmark index this year, the Chinese securities regulator said.

The securities authorities should step up supervision over listed companies to boost accuracy, timeliness and transparency in information disclosure, the China Securities Regulatory Commission said in a statement on its Website yesterday.

China's benchmark stock index has surged 81 percent this year, after more than doubling last year. The rally has made China's stocks the most expensive among the world's major markets, drawing investors in record numbers. Some investors have used all their savings or even pawned their apartments for loans to invest in stocks, the regulator said.

"There are a lot of new investors, who don't have a sense of risk and the capability to bear the risks, coming into the market. Irregularities in the market are mounting," the statement said.

The stock exchanges and authorities should tighten scrutiny of executives at publicly traded companies and stock dealers to prevent price manipulation, the statement said. Companies are barred from using share-sale proceeds to invest in stocks, it said.