India's government has promised to increase compensation for Bhopal gas disaster victims as the 30th anniversary of the tragedy looms, Amnesty International said Saturday.
The pledge was given by India's chemicals minister Ananth Kumar late Friday in New Delhi to demonstrators demanding higher compensation for victims, the rights group said in statement.
Thousands of people were killed when 40 tonnes of lethal methyl isocyanate gas spewed from the Union Carbide chemical plant in the central city of Bhopal on December 2, 1984.
The long-term impact of toxins released after the gas leak led to a string of diseases, which the the state-run Indian Council of Medical Research (ICMR) said had killed 25,000 people by 1994.
Amnesty called the Indian government's enhanced compensation commitment a "major victory" for survivors.
"India's government has agreed to increase a multi-million dollar compensation claim against Union Carbide over the 1984 gas leak... which poisoned more than half a million people," the London-based organisation said.
The group gave no details about the higher compensation, and the Indian government was not immediately available to comment.
But Amnesty said it welcomed the "important move" and called on Prime Minister Narendra Modi to "ensure the government's pledge is honoured".
According to Indian official figures, 3,500 people died within days of the accident.
But the ICMR later estimated the immediate number of deaths at 8,000 to 10,000.
Survivors and their children say they are still afflicted by cancer, vision problems, fatigue, heart disease and other ailments.
Indian authorities blamed the gas leak on design and maintenance problems but Union Carbide attributed it to employee sabotage.
In 2012, the Indian government filed a Supreme Court petition asking for higher compensation from the company, which was set at $470-million in a settlement reached in 1989.
US-based Dow Chemical which bought Union Carbide after the disaster, insists that all of the company's liabilities were covered in a 1989 agreement.