China strongly condemned Japanese Prime Minister Shinzo Abe's visit to the flashpoint Yasukuni shrine in Tokyo on Thursday, saying it glorified Japan's "history of militaristic aggression".
"We strongly protest and seriously condemn the Japanese leader's acts," Beijing's foreign ministry spokesman Qin Gang said in a statement immediately after Abe's visit to the shrine.
China will make "solemn representations" to Japan over his actions, the ministry said.
Yasukuni is believed to be the repository of around 2.5 million souls of Japan's war dead, most of them common soldiers but also including several high-level officials executed for war crimes after World War II, who were enshrined in the 1970s.
"The essence of Japanese leaders' visits to the Yasukuni shrine is to beautify Japan's history of militaristic aggression and colonial rule," Qin said.
China's ruling Communist Party seeks to bolster its public support by tapping into deep-seated resentment of Japan for its brutal invasion of the country in the 1930s.
Before and during World War II Japanese forces swept through much of east Asia, where their treatment of both civilian populations in occupied areas and prisoners of war was appalling, with the Nanjing Massacre one of the worst atrocities recorded.
According to estimates by Chinese government researchers, China lost 20.6 million people directly from the war.
Even now the history is a key element of the backdrop to the two countries' bitter dispute over islands in the East China Sea, which Beijing sees as having been seized by Tokyo at the start of its expansionism.
Qin's statement came after a Chinese foreign ministry official condemned Abe's visit as "absolutely unacceptable to the Chinese people".
Japan "must bear the consequences arising from this", Luo Zhaohui, director-general of the ministry's department of Asian affairs, said in a statement posted on a verified ministry microblog.
He added that the visit, the first by an incumbent Japanese prime minister since 2006, "causes great harm to the feelings of the Asian people and creates a significant new political obstacle to bilateral relations".
The official Xinhua news agency also blasted Abe's action, which it said "would drag Japan's already-fragile relations with neighbouring countries into an abyss".
Users of China's popular social networks responded with fury to the move, with many noting that Abe made his visit on the same day that Chinese President Xi Jinping was paying tribute to Mao Zedong on the 120th anniversary of the former leader's birth.
"Today, Xi Jinping paid homage to Mao Zedong, and Abe paid tribute to the Yasukuni shrine! You both chose the same day! This is a deliberate provocation," wrote one Chinese Internet user.
"The base of Abe's power comes from his confrontation with China, so whatever upsets China, that's what he'll do," another wrote. "No matter what he says about China-Japan friendship, Asian prosperity and joint promotion of peace, it's all a facade."