NANJING, Dec. 18 (Xinhua) -- He Xiaohe, a Nanjing Massacre survivor, passed away on Friday at the age of 91.

His death has reduced the number of registered survivors to 72. Five survivors died this year, according to the Memorial Hall of the Victims in the Nanjing Massacre by Japanese Invaders.

The Nanjing Massacre took place when Japanese troops captured the city on Dec. 13, 1937. Over six weeks, they killed about 300,000 Chinese civilians and unarmed soldiers in one of the most barbaric episodes of World War II.

After the Japanese seized Nanjing, He, then an 8-year-old child, hid in an air-raid shelter with his mother and escaped machine-gun fire from Japanese troops, but he saw Japanese soldiers kill many people at the shelter, according to his earlier testimony.

The Chinese government has preserved the survivors' testimony, recorded in both written documents and video footage. These records of the massacre were listed by UNESCO in the Memory of the World Register in 2015.