China held a memorial ceremony Sunday for victims of the 1937 massacre committed by the Imperial Japanese Army in Nanking, with President Xi Jinping skipping the event after attending last year, as the two countries move toward repairing their often-testy relations.

This year's ceremony in the eastern Chinese city comes after China's successful bid in October to include documents on the military rampage in the "Memory of the World" program by the U.N. Educational, Scientific and Cultural Organization (UNESCO), the U.N.'s cultural agency.

China last year designated Dec. 13 as a national memorial day for the victims and for the first time held a state observance of the tragedy that Beijing says killed more than 300,000.