Tokyo ( CNN ) -- Tens of thousands of people crowded into a park in central Tokyo on Monday to protest the use of nuclear power in Japan , highlighting the growing opposition to atomic energy in the country since the crisis at the Fukushima Daiichi power plant . The peaceful demonstration took place on Japan 's national day in an area the size of a large sports field in Yoyogi Park , near the bustling shopping and nightlife district of Shibuya . The event attracted so many people on a hot July public holiday that many spilled out into the surrounding streets , unable to enter the main area . It brought together a broad mix of Japanese people , from seasoned environmental activists to families who had n't participated in a protest before . The colorful flags dotting the crowd along with the warm weather gave the demonstration the appearance of a summer music festival , but its message was deeply serious . The prominent musician and composed Ryuichi Sakamoto addressed the demonstrators from a stage , calling for an end to nuclear power in Japan . Participants held banners echoing his statements and criticizing the government . Protesters then marched around the surrounding streets , chanting anti-nuclear slogans and drawing traffic to a halt . Demonstrations against atomic energy have become a regular part of Japanese public life since the devastating earthquake and tsunami in March 2011 set off the nuclear disaster at the Fukushima plant . And the protests appear to be gaining momentum . Each Friday , anti-nuclear demonstrators gather outside the Japanese prime minister 's office . That protest has been getting bigger and bigger every week , especially since the Japanese government announced the reactivation of the first nuclear reactor since the Fukushima crisis . Though no deaths have been attributed to the nuclear accident , the earthquake and tsunami killed more than 15,000 people in northeastern Japan . The damaged Fukushima spewed radiation , prompting the government to evacuate tens of thousands of people . A recent report by an independent panel commissioned by the Japanese parliament said the Fukushima crisis was a `` man-made disaster '' that could have been avoided . It criticized the actions of the government , regulators and the plant 's operator , Tokyo Electric Power Co. CNN 's Junko Ogura reported from Tokyo ; Jethro Mullen from Hong Kong .
Protesters walked out of large open spaces in central Tokyo . Anti - nuclear protests are gaining momentum in Japan . The country recently restarted the first nuclear tests since the nuclear accident .