President Xi Jinping said people should never forget the crimes committed by aggressors as the nation marked a new day of commemoration, a bid to highlight Japanese aggression. "Forgetting the history means betrayal, and denying the crime means committing it once again," Xi said at a ceremony marking National Memorial Day for Nanjing Massacre Victims, one of three commemorations established this year - the others are to remember the World War II victory over Japan and the war dead since 1840.

Xi and other leaders visited a hall dedicated to the thousands of 1937 victims and observed a moment of silence in the morning, the Xinhua news agency said.

China-Japan relations deteriorated in 2012 in a dispute over East China Sea islands. - Bloomberg