BEIJING, May 11 (Xinhua) -- China Securities Regulatory Commission (CSRC) urged stock exchanges, securities dealers and related authorities to educate investors in risks of stock market investment in a notice released on Friday.

After four years in the doldrums, China's stock markets began to rebound at the beginning of 2006, with the benchmark Shanghai Composite Index nearly doubling in a year.

These institutions must make investors understand that stock markets are risky and they should be cautious in entering the market, especially for those who use all their savings or pawn their apartments for loans to invest in stocks, the notice said.

The number of new trading accounts opened by individuals in the Chinese mainland's two bourses reached five million in the first quarter of this year, compared with 3.08 million for the whole of last year.

Saying that the number of "irregularities" in the stock market was rising, the CSRC also told listed companies, securities dealers and other related institutions to release accurate, authentic, complete and timely information.