A group of about 100 lawmakers from the ruling Liberal Democratic Party said Tuesday that after a monthlong review they have determined the number of people killed by Japanese troops during the Nanjing Massacre of 1937 has been grossly inflated.

Nariaki Nakayama, head of the group created to study World War II historical issues and education, claimed that documents from Japanese government archives indicate some 20,000 people were killed — about one-tenth of the more commonly cited figure of 150,000 to 200,000 — in the attack. China says as many as 300,000 people were killed.

"We conclude that the death toll in the Nanjing advance was nothing more or less than the death toll that would be expected in a normal battle," Nakayama told a news conference.