The Chinese government said on Thursday that the verdicts of the Tokyo tribunal could not be "overturned" since based on "ironclad" evidence.

Foreign Ministry spokesman Qin Gang made the remarks when commenting on whether the Tokyo Tribunal was discussed at the first joint China-Japan study of history that concluded in Beijing Wednesday.

Qin did not confirm that the topic had been discussed, saying, "History and the international community have given their verdict. There is a mass of ironclad evidence, and it cannot be overturned."

The International Military Tribunal for the Far East (IMTFE), operating from early 1946 until the end of 1948, comprised 11 judges from 11 nations, including the United States, China, the United Kingdom, the Soviet Union and Australia.

The IMTFE held 818 open hearings involving 419 witnesses, accepted 779 written testimonies, and concluded with verdicts totaling 1,231 pages which took seven days to read.

The verdicts were formed on the basis of international laws, a wealth of witness testimony and material evidence.

Qin said that although scholars of both countries may have different opinions, their research should evolve through objective facts, and in a spirit of responsibility for history, the future and the people.

Altogether 20 Chinese and Japanese historians gathered in Beijing on Tuesday and Wednesday for the first-ever joint historical research to narrow differences between the two countries on historical issues.

The Chinese team was headed by Bu Ping, director of the Chinese Academy of Social Sciences' Institute of Modern History. The Japanese team was led by Shinichi Kitaoka, former deputy Japanese ambassador to the UN and a professor with the University of Tokyo.

During the two-day closed-door meeting, both sides settled the work process, scope and topics of the joint research, and discussed the history of China-Japan exchanges spanning more than 2,000 years as well as modern and post-World War II history in two groups.

The second meeting of this kind will be held in March 2007 in Japan to further discussions of historical issues.

Also on Thursday, Qin said Chinese leaders would visit Japan at a convenient time next year, but stopped short of confirming a report stating Premier Wen Jiabao would visit Tokyo in April.

"China and Japan have agreed in principle that Chinese leaders will visit Japan at a time convenient for both sides," Qin told a regular news briefing. "But the specific date for the visit has yet to be set through diplomatic consultations."

A Japanese newspaper Nihon Keizai Shimbun reported on Wednesday that Wen is set to visit Japan in April - the first such visit in over six years.

The Asian neighbors hope the visit will improve bilateral ties, which deteriorated to their worst level in decades over former Prime Minister Junichiro Koizumi's visits to a controversial Tokyo war shrine, the Nihon Keizai Shimbun said in its evening edition.

"We have noticed the report," Qin said. "Related information will be released as soon as we get it."

Commenting on whether Israeli Prime Minister Ehud Olmert is set to visit China, Qin said he did not have any information.

"China and Israel have exchanges and cooperation at various levels and in various fields," Qin said. "We have had no information about the Israeli leader's visit to China. If any, we will make it public at a proper time."

At the news briefing, Qin also lauded the efforts made by the Secretary-General of Shanghai Cooperation Organization (SCO) Zhang Deguang, who will conclude his three-year term at the end of this year to be succeeded by Bolat Nurgaliyev from Kazakhstan.

"During Zhang's three-year term, the SCO secretariat worked in an efficient, orderly and co-ordinated manner," Qin said.

Currently, political mutual trust has been intensified among the SCO members along with a deepening of pragmatic cooperation, and the influence of the organization on the international community has been rising, he said.

In another development, China on Thursday expressed condolences and sympathy for Tuesday's oil pipeline explosion in Nigeria, which caused hundreds of deaths.

The oil pipeline explosion occurred early Tuesday in Nigeria's commercial capital Lagos which burned more than 200 people to death.

The victims were local residents who had been scooping fuel from a vandalized petrol pipeline. Stealing fuel from oil pipelines is a common illegal occurrence in Nigeria.

(Xinhua News Agency, China Daily December 29, 2006)