The central government was on Saturday asked to reopen all closed cases and re-investigate the 1984 massacre of over 3,000 Sikhs following the assassination of the then prime minister Indira Gandhi.
A large number of people participated in an online campaign by Amnesty International India in Delhi and Bangalore to call for justice to the 1984 carnage victims.
Amnesty International India Programmes Director Shailesh Rai said in Delhi: "This year marks 30 years of impunity for the crimes committed during one of India's most shameful episodes. It is a national disgrace that thousands of victims and survivors of the 1984 violence have been denied justice for three decades now."
The people also urged the government to establish an independent team to conduct thorough, impartial and effective investigations into all cases, including closed ones, of all anti-Sikh violence in 1984.
Rai said though official inquiry commissions were appointed to investigate the massacre, and some found evidence of complicity of police officials and Congress leaders, nothing concrete was done to punish them.
He said: "The Indian government cannot continue abdicating its responsibility to punish those who were behind the violence against Sikh men, women and children in 1984. Authorities must heed the voices of the thousands who are calling for justice."
He added: "The sheer scale of the impunity for the 1984 massacre is staggering, and has also been used to downplay other incidents of mass violence. As long as the perpetrators of the carnage go unpunished, the rule of law in India remains weakened."