Worries about the health of China’s economy shook markets again Friday, hitting stocks in Asia and Europe.

Signs of a sharp slowdown in the world’s second-largest economy have rattled investors since Beijing surprised markets last week by devaluing its currency.

On Friday, an early gauge of China’s factory activity fell to a six-and-a-half year low in August, heaping further pressure on beleaguered stocks and commodities.

The Shanghai Composite Index tumbled 4.3%, hitting its lowest level since March despite Beijing’s efforts to prop up the market in recent weeks. In Japan, the Nikkei fell 2.6% to a six-week low.

“It becomes ever more evident that China’s economy is cooling off,” said Jeroen Blokland, a portfolio manager at Robeco, which manages $307 billion of assets.

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