A group of families demanding justice for victims of China's 1989 Tiananmen Square crackdown declared that the government must bear responsibility for historical crimes in the same way it has called on Japan to do so for its wartime past.

The Tiananmen Mothers activist group has long urged the leadership to open a dialogue and reassess the 1989 democracy movement, violently suppressed on June 4 that year by the government, which labelled it "counterrevolutionary."

In an open letter released on Monday through New York-based Human Rights in China, the group cited Premier Li Keqiang's remarks on Japan's failure to reflect on its past.