The European Union (EU) would conduct "stress tests" on its member states' nuclear power plants in the wake of Japan's nuclear crisis, the bloc's energy chief Guenther Oettinger said on Tuesday.

The tests would include risk assessments of possible damage by earthquakes and high water levels, Oettinger told the European Parliament's Energy Committee.

The development came as fears of a nuclear meltdown mounted over Japan's Fukushima nuclear plant, which was seriously affected by a 9.0-magnitude earthquake on Friday and the massive tsunami that followed.

The tests would be concluded by the end of the year, Oettinger said, adding that thorough stress tests would also take place in nuclear plants of neighboring countries including Turkey, Russia and Switzerland.

Any decision on the early closure of nuclear power plants or on a moratorium on the construction of future plants, however, lies with national governments and public opinion in the EU member states, he said.

Europe now has about 143 nuclear power plants in 14 countries.

Earlier on Tuesday, Germany announced that it would shut down seven of its oldest nuclear reactors built before 1980 for three months while it conducts a safety probe.