The German DAX closed provisionally down 2.5 percent on the day, the French CAC was down 2.2 percent and the U.K.'s FTSE 100 was 1.8 percent lower.
U.S. stocks indexes also traded lower on Friday and sovereign bond yields continued to slide.
Benchmark 10-year German bund yields fell to an all-time low of 0.011 percent, leaving traders mulling if a 0 percent or negative yield loomed. Yields then recovered slightly in late European trade.
"I think everyone is spooked by European stocks, especially the DAX, getting slammed today ... If the German 10-year bund yield gets below 0, they're just spooked by that," Jeremy Klein, chief market strategist at FBN Securities, said.
"I think it's a combination of, this is not good for financials and is this emblematic of what's going with the economy?" he added.