TOKYO, Aug. 3 Kyodo - Japan expressed regret Tuesday over an accident last month in northeastern China in which two children were injured by gas that leaked from a mustard gas shell left by the Japanese military at the end of World War II.

''We feel it is quite regrettable and extend our sincere sympathy to the victims,'' Foreign Ministry spokesman Hatsuhisa Takashima said in a statement as the government reached a conclusion that the shell was one left by the Japanese military.

The ministry announced Tuesday that the government reached the conclusion through a survey by a fact-finding mission sent to the site.

''In order to dispose of its chemical weapons left in China as early as possible, Japan will take appropriate measures in line with its obligations under the Chemical Weapons Convention,'' he said.

On July 23, two children playing in a river in Dunhua, Jilin Province, discovered a 75-millimeter mustard gas shell. Gas from the shell leaked, injuring their legs and hands, according to Chinese and Japanese accounts last week.

Two other accidents involving Japanese chemical weapons left in northeastern China have been reported over the past year. One incident killed a construction worker and injured 43 others in August last year in Qiqihar, Heilongjiang Province.

Japan occupied northeastern China from 1931 to 1945.

==Kyodo