Survivors and relatives of the victims of the Bhopal gas disaster holding torches during a torch-light rally on the eve of the 36th anniversary of the tragedy in Bhopal on Wednesday.
A gas leak at a Union Carbide Corporation plant in Bhopal on Dec 3, 1984 killed at least 15,000 people in what is considered the world's worst industrial accident.
Some half a million survivors suffered respiratory problems, eye irritation, blindness and other maladies.
Investigations revealed substandard operating and safety procedures at the understaffed plant had led to the catastrophe.
India marks National Pollution Control Day on Dec 2 in honour of the people who died in the horrific incident in Bhopal.