At least 1000 anti-nuclear activists on Sunday marched through Tokyo as workers battled to stem the damage from a leaking atomic reactor.
The Japan Congress Against A and H Bombs hold such marches every month but this month’s demonstration attracted a better turnout after they advertised the rally on social networking sites.
A group of Greenpeace radiation experts have been analysing the area that surrounds the Fukushima nuclear plant.
The environmental pressure group said Japanese officials have been too quick to underplay the disaster’s impact and the threat posed to public health.
Greenpeace sent a team to Fukushima to provide an alternative to what it called “often contradictory information” issued by regulators.