Two of China's top newspapers accused Japanese Prime Minister Shinzo Abe on Thursday of dangerous politics that could threaten regional security, as Tokyo warned Beijing not to expand gas exploration in disputed waters of the East China Sea.
The People's Liberation Army Daily said Abe was trying to play the "China threat" angle, to win votes in July 21 elections, with a visit on Wednesday to Japan's southern island of Ishigaki, near islets claimed by both China and Japan.
Territorial claims by Japan and China over the uninhabited islets and resource-rich waters in the East China Sea, as well as China's claims over the South China Sea, rank as some of Asia's biggest security risks.
During the visit to Ishigaki island, Abe repeated Tokyo's stand that the nearby disputed Senkaku islands, called the Diaoyu by China, are inherent Japanese territory, adding that he has no intention of conceding even one step.
"This kind of 'drinking poison to slake ones thirst' not only threatens regional stability, it gives encouragement to Japan's 'turn to the right'," said the daily.
Abe wants to revise Japan's constitution, drafted by the United States after World War Two, to formalise the country's right to have a military. Critics say his plan could return Japan to a socially conservative, authoritarian past.
The People's Liberation Army Daily said Abe could not have chosen a worse time to visit Ishigaki, which lies some 160 km (100 miles) from the uninhabited islets the two nations contest.
"You cannot criticise a national leader for visiting his country's own territory but in a situation where the dispute over the Diaoyu Islands is continuing and the situation is complex and sensitive, Abe's actions are doubtless extremely dangerous and irresponsible," the paper, the official publication of China's military, said in a commentary.
The ruling Communist Party's official People's Daily warned that China would never allow itself to be trampled on again, a reference to China's bitter memories of Japan's invasion of the country ahead of and during World War Two.
In a commentary published under the pen name "Zhong Sheng", or "voice of China", the newspaper said that Abe was looking for excuses to re-arm Japan and that the dispute with China was a convenient way of pushing this.
"The aim is to create tension and provoke incidents, to push Japan's military development," it said.
Patrol ships from both nations routinely shadow each other near the islands, raising concerns about an unintended clash.
On Thursday, three Chinese surveillance vessels sailed into what Japan considers its territorial waters near the isles on what Beijing said was a routine patrol.
The Japan Coast Guard said the ships later left its territorial water but remain in the contiguous area.
The territorial dispute between China and Japan was further complicated on Wednesday with news that Chinese state-run oil companies plan to develop seven new gas fields in the East China Sea, possibly siphoning gas from the seabed beneath waters claimed by Japan.
Beijing had slowed exploration in the energy-rich East China Sea but is now rapidly expanding its hunt for gas, a cheaper and cleaner energy to coal and oil imports.
Japanese Chief Cabinet Secretary Yoshihide Suga said his government had asked China about the plans, first reported by Reuters.
"If the Chinese side is to proceed unilaterally with development in the area over which there are conflicting claims, Japan would never accept it," Suga told a regular news conference on Thursday.