TOKYO — Evidence submitted to the post-World War II trials of Japanese war criminals shows Japan’s military forced Asian women into sexual slavery during the war, historians said Tuesday, citing newly unearthed documents.

The findings from the mass of evidence submitted at the 1946-48 Tokyo war crimes tribunal contradict Prime Minister Shinzo Abe’s recent denial that the military coerced women to be prostitutes for its troops — remarks that triggered outrage in South Korea and China.

In one document dated March 13, 1946, and unearthed last year by Kanto Gakuin University historian Hirofumi Hayashi, Dutch prosecutors quote an Imperial Navy employee as saying women in occupied Indonesia were rounded up on phony charges so they could be forced into brothels.

“I admit to have slapped these women with the flat of my hand; I also ordered them to undress,” the document quotes Shuichi Hayashi as saying. “I do not think these women were actually punishable, but their arrest ... was only a pretext to put them in a brothel.”

The main verdict at the Tokyo tribunal — accepted as valid by Japan’s government in the 1952 peace treaty between Japan and the Allied Powers — also says the Japanese military forced women to have sex with its troops.

“These are clear cases of women being coerced into brothels,” Hayashi said at a news conference attended by other historians. “These documents have been long known to the Japanese government. I don’t know how they can ignore these.”

Historians say hundreds of thousands of women, mainly from Korea, the Philippines and China, were forced into Japanese front-line brothels in the 1930s and ’40s.

After decades of denial, the Japanese government acknowledged its role in wartime prostitution after another historian, Yoshiaki Yoshimi, discovered documents showing government involvement.

That led to an official — though carefully worded — apology in 1993, and the establishment of a nongovernment fund to pay the women limited reparations.

But right-wing politicians, who make up an important part of Abe’s base, have renewed efforts to roll back the apology. They say the women were professional prostitutes and Japanese commanders were not responsible for setting up brothels.

Yoshimi, speaking at the same news conference, said that argument was refuted by the evidence already acknowledged as valid by the Japanese government and called on Japanese leaders to offer an unequivocal apology as well as compensation.

“The evidence is clear that the system of ’comfort stations’ was set up, maintained and enlarged by the Japanese military itself,” he said. “The government must issue a clearer message that responsibility lies with the military ... Japan should also accept legal responsibility, and offer individual compensation.”

The new evidence comes as a committee of the U.S. House considers a nonbinding resolution calling on Japan to fully acknowledge wrongdoing and make an unambiguous apology. Japan has objected to the resolution, arguing it is not based on historical fact.