Thousands of anti-nuclear protestors have marched in Japan, three months after an earthquake and tsunami triggered the worst nuclear disaster in 25 years.

Three reactors went into meltdown after the earthquake hit the Fukushima Daiichi plant in northeastern Japan, forcing 80,000 residents to evacuate from its vicinity as engineers battled radiation leaks, hydrogen explosions and overheating fuel rods.

Company workers, students and parents with children on their shoulders rallied across Japan, venting their anger at the government's handling of the crisis, carrying flags bearing the words ‘No Nukes!’ and ‘No More Fukushima’.

The protests are likely to add to public pressure that caused a shutdown of the Hamaoka nuclear plant in May and delays to the restart of reactors across the country after scheduled maintenance until tighter safety measures are put in place.

In France, where nuclear plants produce 75% of energy output, police said 1,150 people joined a protest in Paris. The anti-nuclear campaigners who organised the rally said 5,000 took part.

Japan is running just 19 of 54 reactors in operation before the Fukushima disaster, raising the risk of serious power shortages into 2012. Many experts say economic risks are too high for Japan to pull the plug on all its reactors.

Analysts say industry is facing more power rationing and the need for energy imports levies a high price on the world's third-largest economy. Japan lacks the electricity generation capacity to substitute for the nuclear fleet.

Japan's anti-nuclear movement, small and ignored by the public until the Fukushima crisis, has become more vocal, gathering increasing numbers of people to demonstrations.