Chinese and Japanese experts, wearing protective gears, work at a excavation site at Touzhan Village in the Ang'angxi District of Qiqihar, Northeast China's Heilongjiang Province, where chemical bombs left by invading Japanese troops during World War II were found. [newsphoto]

The two governments will request the Organization for the Prohibition of Chemical Weapons to extend the deadline to spring of 2012 as there are still an estimated 300,000 to 400,000 shells in Dunhua, Jilin Province, left by the former Imperial Japanese Army at the end of World War II, they said.

Japan has collected and disposed of about 40,000 shells in China since 2000 under the Chemical Weapons Convention that requires it, but large portions of the abandoned shells remain untreated in the Harbaling area in Dunhua due to a delay in work to construct essential disposal facilities in the area.

The Chinese government has not given permission to the Japanese government's plan to build the facilities in the city, and the Cabinet Office has cited the Chinese side's difficulty in deciding which administrative branch will deal with the unprecedented project.

Japan has ratified the convention, which came into force on April 29, 1997. The treaty requires contracting states to remove within a decade chemical weapons they left in other contracting states.

Contracting states can also extend the deadline by submitting a request by a year before the deadline under the treaty.

Collection and disposal of chemical weapons in China is an urgent issue for Japan as a number of Chinese people have been killed or injured by toxic gas leaking from dumped shells on various occasions, such as while working at construction sites, in the postwar era.