The International Labour Organization has listed the Bhopal gas tragedy among the world’s major industrial accidents in the last century.

The release of gas from a pesticide plant in Bhopal in 1984 affected over 6 lakh workers and people who lived in the area nearby, the United Nations labour agency said in a report released on Thursday. At least 30 tons of methyl isocyanate was released from the plant, it added.

“Government figures estimate that there have been 15,000 deaths as a result of the disaster over the years,” the ILO said in its report “Safety and Health at the heart of the Future of Work: Building on 100 years of experience”.

“Toxic material remains and thousands of survivors and their descendants have suffered from respiratory diseases and from damage to internal organs and immune systems,” the report said.

The report listed nine major industrial accidents since 1919. Apart from the Bhopal gas tragedy, its list included the 1986 Chernobyl nuclear power plant explosion in the erstwhile Soviet Union, the 2011 Fukushima disaster and the collapse of the Rana Plaza building in Dhaka, Bangladesh, in 2013, which killed 1,132 people.

In January, the Supreme Court of India agreed to hear the Centre’s curative petition seeking Rs 7,844 crore from the successor companies of Union Carbide, to provide compensation to the victims of the Bhopal gas tragedy. The court said the plea will be heard in April.

The gas leak in the Union Carbide pesticide plant in Bhopal on the night of December 2 and 3, 1984, killed over 3,500 people, according to state government figures. Union Carbide, which is now owned by Dow Chemicals, and other firms have so far paid $470 million (Rs 3,261 crore) as compensation to the Indian government.

The erstwhile United Progressive Alliance government had filed a petition in 2010 seeking compensation from Union Carbide’s successor firms. It had put the toll at 3,000 and the number of injuries at 70,000. However, the National Democratic Alliance government’s curative petition puts the number of deaths at 5,295, and the number of wounded at 5,27,894. The Centre said in its plea that the earlier estimates did not account for the deaths and losses caused due to environmental degradation following the disaster.