A new diary released at a seminar on December 12 in northeast China's Liaoning Province offers more details into the notorious Nanjing Massacre by Japanese troops that led to 300,000 deaths in 1937.

The 198-page dairy, written by a Japanese soldier from 1937 to 1939, is more than 30,000 words long and details dozens of battles and fights that he participated over the two years, including the Nanjing Massacre.

Experts have verified the authenticity of the diary and have translated the parts concerning the massacre into Chinese, said Mao Wei, collector of the diary, at the seminar held a day before the National Memorial Day for Nanjing Massacre Victims.

"Nanjing was covered by black smoke since the [December] 12, and fire brightly burning can be seen everywhere," the diary says. "Many bodies of the enemies lay outside the city gate. The battle was so massive in scale that the whole city was scorched."

Wang Jianxue, Deputy Head of China Association of Historians Studying Modern Chinese Historical Materials, said the diary recorded a series of facts around Nanjing Massacre from the perspective of an aggressor, and was of great historical value.

"It also offers new evidence for the crimes that the Japanese aggressors committed in China," Wang said.