Mothers of some of those killed in the bloody crackdown on China's 1989 Tiananmen pro-democracy movement are condemning the Chinese government for failing to account for their children's deaths and vowing to continue pushing for the truth ahead of this weekend's 27th anniversary of the events.

Published by the advocacy group Human Rights in China, the letter signed by 131 mothers said victims' families continue to suffer from harassment and intimidation by Chinese security services for pursuing their quest for justice for their loved ones.

The letter condemns the Chinese government for its apathy, accusing Beijing of ignoring pleas by family members and wiping out public memories of the movement and the bloody crackdown on the night of June 3-4, 1989, in which hundreds, possibly thousands were killed.