A new study shows high levels of radioactive contamination in the Japanese city of Fukushima, some 60 kilometers from the site of the world's worst nuclear disaster in a quarter-century.

Two groups who backed the non-governmental study linked the findings on Wednesday to radioactive leaks at the Fukushima-Daiichi nuclear power plant, which was battered and disabled by a massive earthquake and tsunami on March 11. Researchers urged the government to encourage evacuations from the city, saying soil contamination measured more than 30 times higher than current government safety standards at test locations.

Government authorities have not commented on the findings, which were released two days ahead of a visit by a team of nuclear cleanup experts from the International Atomic Energy Agency.

The 12-member IAEA team is expected In Tokyo Friday, and will visit several locations in Fukushima prefecture during its 9-day stay. The team will also consult with authorities in Tokyo to review cleanup strategies at and near the shuttered power plant.