Tens of thousands of people rallied in Tokyo on Monday demanding an end to nuclear power, the latest in a series of anti-atomic gatherings following the tsunami-sparked disaster at Fukushima last year.
Demonstrators marched through streets near Yoyogi park under scorching sunshine on a national holiday, chanting in chorus: "Don't resume nuclear power operation. Prime Minister (Yoshihiko) Noda should quit."
Organisers said the number of participants was estimated to reach 170,000, one of the biggest anti-nuclear rallies since the March 2011 quake-tsunami sparked the world's worst atomic disaster in a generation.
"We are so angry because no progress has been made in terms of compensation and decontamination," said Noboru Shikatani, a 71-year-old man who evacuated Fukushima to go to Tokyo following the disaster.
"We can't accept any resumption of nuclear power operation as the Fukushima case has not been resolved at all," Shikatani added. "We want to bring our voice to many people by joining this kind of demonstration."
Participants included Nobel-winning author Kenzaburo Oe and Japanese musician and composer Ryuichi Sakamoto.
"I dare to say it is merely a matter of electricity," Sakamoto told the gathering from a stage. "Why do we have to expose our lives to danger only for the sake of power?"
But Noda defended his decision to resume nuclear power, telling a television interview: "We made a political decision after carrying out strict stress tests and getting through procedures in the safety committee and agency."
The latest rally came a week after a nuclear reactor in western Japan began full operations, the first restart since the country shut down its atomic stations in the wake of the crisis.
The return to full operations ended a nearly two-month hiatus in the aftermath of the atomic crisis, but came amid strong anti-nuclear sentiment in Japan which has seen protesters come out in their tens of thousands.
A damning parliamentary report said the accident at the Fukushima Daiichi plant was a man-made disaster, marked by a lack of oversight and collusion between plant operator Tokyo Electric Power, the government and regulators.
Nuclear power was put on hold as the government mulled its options following the 9.0-magnitude earthquake and tsunami that crippled reactor cooling systems at Fukushima.
But last month Noda gave the green light to restart two reactors at the Oi plant in Fukui prefecture, western Japan, amid concerns about looming power shortages this summer.
"We want to continue to stage demonstration as anti-nuclear sentiment is growing steadily among people," Yasunari Fujimoto, an organiser of the rally, said.