Data from Germany showed exports fell 2.6 percent in July. This was the latest piece of bad news about Germany's economy, following disappointing manufacturing data earlier in the week.
Meanwhile, yields on 10-year German Bunds turned positive for the first time since June 22. Yields were around 0.013 percent at the time of the market close, up from -0.06 percent on Thursday.
"The jolt across bond markets began when ECB president Mario Draghi said the governing council did not discuss extending its asset purchase program. Understandably, bondholders got a little nervous about holding onto a negative-yielding asset which could fall in price if there's no central banking buying alongside them," Jasper Lawler, market analyst at CMC Markets, said in a note on Friday.
Investors were left disappointed after the ECB kept its benchmark refinancing rate at 0 percent on Thursday and did not change its trillion-euro bond-buying plan, saying the program would run until the end of March 2017 or beyond if necessary.