China's securities regulator on Saturday released draft prospectuses for a small group of companies planning to list, in a move that may soothe investor concerns that the country had put in place a de facto freeze on IPOs.

The 28 prospectuses, published on the website of the China Securities Regulatory Commission (CSRC), included Well Lead Medical, a medical equipment firm in the southern city of Guangzhou, and Hangzhou Weiguang Electronic Co Ltd, which makes motors for electric fans.

But it is unclear whether, or when, the companies will be approved to list.

Sixteen of the companies on the list are applying for the main board of the Shanghai Stock Exchange, eight for the ChiNext Board and four for Shenzhen's small- and medium-sized enterprises board.

The CSRC told investors last week that China had not closed its window for IPO applications.

No new companies have listed for nearly two months, leading Chinese media to speculate that an informal freeze is in place.

China allowed initial public offerings to resume in early 2014 after a hiatus of 14 months, allowing around 50 already approved companies to list on the Shanghai and Shenzhen exchanges.

More than 600 companies are still in the queue.