Japan said Tuesday it was "quite regrettable" that two children were injured by a leaking chemical weapon dumped in northeastern China by the departing Imperial Japanese Army at the close 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.

A fact-finding mission sent to the site earlier this week has concluded that the mustard gas shell was discarded by the Japanese military, the ministry said.

"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 near a river in Dunhua, Jilin Province, discovered a 75 mm mustard gas shell. Gas from the shell leaked, injuring their legs and hands, according to Chinese and Japanese accounts last week.