OSAKA — Three Japan-based antinuclear groups called Monday on the International Atomic Energy Agency to carry out a comprehensive, unbiased probe into the earthquake damage at the Kashiwazaki-Kariwa power plant in Niigata Prefecture.

They also said the IAEA should vigorously pursue not only what happened but why the complex was allowed to be built on an active fault line.

The groups have demanded that the four-day IAEA investigation that began Monday not yield a hasty conclusion that the damaged seven-reactor complex, the world's largest in terms of power output, could at some point in the future be restarted.