Asian markets mostly fell again Wednesday as fears over China's regulatory crackdown continued to reverberate around trading floors, while analysts said companies might struggle to maintain their recent run of blockbuster earnings results that have sent valuations soaring.

Hong Kong and Shanghai were in focus after suffering a diabolical previous three days in the wake of Beijing unveiling a series of measures aimed at curbing a range of industries -- including tech and private tuition -- that have raised fears of further action.

The struggles in Asia were reflected in New York, where the Nasdaq led losses. And while some of the selling was down to profit-taking after all three indexes hit records on consecutive days, analysts said unease about China's moves played a role.

"The turmoil in tech stocks in China is finally bleeding into US tech stocks," said Chris Murphy, of Susquehanna International Group, adding that he was "concerned investors will lighten up in general" after major tech earnings heading into "a seasonably weak period for equities".

Murphy's comments came as Apple, Google-parent Alphabet and Microsoft all announced better-than-expected results, but their after-hours share prices dropped.

"The key takeaway from this wrath of earnings was that risk appetite will likely struggle going forward given the persistent struggles with supply chains, concerns over growth in China, and uncertainty over how much more monetary and fiscal support this economy will see," said OANDA's Edward Moya.

"Wall Street has priced in lower interest rates for longer and now we need to see if the current delta variant concerns will make the Fed push back any hint of taper announcement until the end of the year."

Eyes will be on the Federal Reserve's latest policy meeting, which ends later Wednesday and will be closely watched for any guidance on its plans in light of the economic recovery, reopening and spread of the Delta variant that has sent infections spiking.

In afternoon trade, Hong Kong rose more than one percent but oscillated wildly and made only a small dent in the more than nine percent drop suffered over the previous three days.

Tuition firms enjoyed some respite but tech giant Tencent continued to suffer selling pressure, with further pressure on the firm after China ordered developers to address problems linked to pop ups in their apps.

Shanghai fell again, while there were also losses in Tokyo, Sydney, Singapore, Taipei, Manila, Mumbai and Jakarta. Seoul and Wellington inched higher.

London dipped at the open but Paris and Frankfurt eked out small gains.

In light of the recent rout and in a bid to remove some volatility, Chinese mainland state media has looked to soothe investor nerves, saying markets were likely to stabilise soon and that the new rules would prove beneficial to the economy in the long term.

Securities Times said in a front-page editorial that the sell-off had "to an extent, reflected the misreading of policies and venting of sentiment by some funds" but that economic fundamentals were unchanged.

"While adjustment of policies in some industries may affect their current business model, it will be beneficial toward unleashing more social vitality in the mid-to-long term and aid consumption in most other areas," it added.

Meanwhile, the China Securities Journal said there was no need for pessimism while the Shanghai Securities News cited analysts as saying the falls provided decent buying opportunities.

Bitcoin was sitting around $39,500 following a recent rally that has helped it briefly break $40,000, helped by renewed support from tycoon Elon Musk and other investors, with some analysts saying it could test the $45,000 mark again.