Futures on the Euro STOXX 50, German DAX and French CAC indexes fell between 2.5-2.7 percent by 0702 GMT.
Futures on Britain's FTSE 100 fell 1.9 percent.
The People's Bank of China (PBOC) again surprised markets by setting the official midpoint rate on the yuan, also known as the renminbi (RMB), at 6.5646 per dollar, the lowest since March 2011.
China's stock markets were suspended for the rest of the day less than half an hour after opening as a new circuit-breaking mechanism was tripped for the second time this week.