Japan's newly-appointed Chinese ambassador dies September 17, 2012 -- Updated 0702 GMT (1502 HKT) Shinichi Nishimiya (C) pictured in 2005 at a meeting of the Association of Southeast Asian Nations (ASEAN). Japanese Foreign Ministry confirms Shinichi Nishimiya, 60, died on Sunday Nishimiya was due to replace the current Japanese envoy in Beijing -- Uichiro Niwa His death comes amid worsening relations between China and Japan Both countries claim sovereignty over a group of islands in the East China Sea Hong Kong (CNN) -- The newly appointed Japanese ambassador to China has died after taking ill and collapsing in Tokyo late last week. In a brief statement, the Japanese Foreign Ministry confirmed Shinichi Nishimiya, 60, died on Sunday after spending the weekend in hospital because of his "health condition." He collapsed just two days after being appointed to the job. The ministry did not disclose any further details about what had happened. Panasonic closes China plants after protests Previously a deputy minister for foreign affairs, Nishimiya was due to replace the current Japanese envoy in Beijing, 72-year-old Uichiro Niwa, in the coming weeks amid heightened tensions between Japan and China. The Japanese government's recent purchase of a set of disputed islands in the East China Sea from a private owner has angered Beijing, which has called the acquisition "illegal and invalid." Asian islands dispute: Who claims what? On Friday China sent six surveillance vessels to carry out patrols around the remote islands, which Japan calls Senkaku and China calls Diaoyu, in an effort to underscore its claim to sovereignty. The dispute also hit a nerve with many ordinary Chinese, as tens of thousands took to the streets at the weekend to protest against Japan's stance. In Beijing, Japan's embassy was attacked with eggs and bottles, while angry mobs in other cities across China ransacked Japanese businesses and burned Japanese-made cars. iReport: Caught in anti-Japan protest Though Japanese officials have sought to play down the significance of the deal to buy the islands, the dispute has come to represent what many Chinese people see as unfinished business: redressing the impact of the Japanese occupation of large swathes of eastern China during the 1930s and 1940s. CNN's Junko Ogura contributed to this report. September 17, 2012 -- Updated 0905 GMT (1705 HKT) The current wave of anti-Japanese protests sweeping China can be traced back to April and the firebrand governor of Tokyo.