NANJING - Eleven survivors of the Nanjing Massacre have passed away this year, according to the Memorial Hall of the Victims in the Nanjing Massacre by Japanese Invaders on Friday.

Their deaths reduced the total number of registered survivors to 61, with an average age of 91, according to the memorial hall.

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

In 2014, China's top legislature designated Dec 13 as the national memorial day for the victims of the Nanjing Massacre.

The Chinese government has preserved the survivors' testimonies by recording them in written documents and video footage. UNESCO listed these records of the massacre in the Memory of the World Register in 2015.