Vice President Hamid Ansari said the tragedy, in which thousands of people died because of a gas leak from a Union Carbide pesticide plant, left a legacy of birth deformities, the Press Trust of India reported.
"The tragedy still haunts us in the form of incapacitated people and children born with deformities," Ansari said in a ceremony at Rajya Sabha. "It was indeed a human tragedy of unparalleled magnitude, which shocked the conscience of the world."
The Indian government said about 3,500 people died within days of the Dec. 2, 1984, leak and more than 15,000 since.
The tragedy has been compounded since the leak because of an "indifferent attitude," Ansari said. "It is incumbent on us, morally and legally, to do our utmost to support the surviving victims in every manner possible."
In a Lok Sabha memorial, legislative leader Meira Kumar said a pledge should be taken to adopt measures to prevent similar incidents in the future, PTI said.
In a move that coincided with the anniversary, Indian officials announced they would seek $1.1 billion in compensation from Union Carbide -- more than double the settlement reached in 1989, the BBC reported.
In June, an Indian court convicted seven former managers at the plant, ordering them to pay minor fines and serve brief prison terms.
However, victims and their supporters have said they don't think justice was served, the British broadcaster said.
Dow Chemical, which bought Union Carbide in 1999, has said the $470 million settlement was fair and final.
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