NANJING, Dec. 13 -- Chinese President Xi Jinping on Saturday attended the state ceremony for China's first National Memorial Day for Nanjing Massacre Victims.

Other Communist Party of China (CPC) and state leaders were also present at the ceremony held at the memorial hall for the massacre victims in the east China city of Nanjing.

Japanese troops captured Nanjing, then China's capital, on Dec. 13 of 1937 and started a slaughter of 40-odd days. More than 300,000 Chinese soldiers, who had laid down their arms, and civilians were murdered and about 20,000 women were raped.

In February 2014, China's top legislature decided to set Dec. 13 as the National Memorial Day for Nanjing Massacre Victims to mourn Nanjing Massacre victims and all those killed by Japanese invaders, and to reveal war crimes committed by the Japanese.

The move was aimed at remembering the deep calamities the war caused for the Chinese people and people around the world, conveying the Chinese people's firm stance of resisting aggression and safeguarding human dignity and world peace, according to the decision passed by the Standing Committee of the National People's Congress.

It is the third time this year for President Xi to attend high-level activities relating to Japanese aggression to China.

He attended a ceremony on July 7 to mark the start of the War of Resistance Against Japanese Aggression in 1937 and a victory day celebration on Sept. 3 for the 69th anniversary of winning the war against Japanese aggression.