New York, April 26 (IANS) Human Rights Watch (HRW) has sought the prosecution of leaders of India's Congress party who allegedly organised attacks on Sikhs after Indira Gandhi's assassination in 1984.

Sikhs were attacked and killed "with the complicity of senior members of (then prime minister) Gandhi's Congress party," said HRW South Asia director Meenakshi Ganguly.

"Although there is evidence that at least some of the attacks were orchestrated by senior political figures, none have yet been convicted for the 1984 killings," she said.

"The discovery of more Sikh massacre victims after nearly three decades shows the reluctance of successive Indian governments, despite numerous commissions of inquiry, to get to the truth and prosecute those responsible for the anti-Sikh violence," Ganguly said.

Referring to the recent discovery of mass graves in Hondh-Chillar in Haryana, she said: "The Haryana massacre is a reminder that India needs a law that will provide maximum protection against orchestrated attacks on minorities.

"The government should listen to all suggestions that could strengthen the communal violence bill so that these outrages never happen again."

A case against Congress party has been filed in a New York court by the US based Sikhs for Justice (SFJ) along with several Sikh individuals from different states and cities of India who witnessed and survived attacks in 1984.