Lawyers representing victims of an August mustard gas leak from Japanese wartime chemical weapons abandoned in China submitted a petition Friday to Prime Minister Junichiro Koizumi, demanding an official apology and compensation for the victims and their families.

The wife of Li Guizhen, who died from the leaked gas at a construction site in Qiqihar, Heilongjian Province, entrusted the Japanese lawyers earlier in the day to enter negotiations with the Japanese government. The August incident also injured 40 others.

Toshitaka Onodera, head of the legal team, told a news conference in Tokyo that they want to meet directly with Koizumi or Chief Cabinet Secretary Yasuo Fukuda on Monday to discuss the issue.

"We want to resolve the issue primarily through negotiations, but if the government refuses to negotiate, we have also been entrusted with the authority to file a lawsuit," he said.

Regarding the August incident, the government has promised to take "a sincere stance" on the matter and has sent investigative teams and doctors to China. But on a reported plan to pay 100 million yen as a token of "sympathy," Foreign Minister Yoriko Kawaguchi told the Diet on Wednesday that the government had not made such a decision.

Responding to Friday's petition, Fukuda later said that he sees no need to meet the lawyers, as Japan is currently discussing the issue with China.

"We will resolve the issue through talks with the Chinese government," Fukuda told a regular news conference. "We have been taking a sincere stance and doing what we can."