A court in the Indian city of Bhopal has sentenced eight people to two years each in jail over a gas plant leak that killed thousands of people in 1984.
The convictions are the first since the disaster at the Union Carbide plant - the world's worst industrial accident.
The eight Indians, all former plant employees, were convicted of "death by negligence". One had already died - the others are expected to appeal.
Campaigners said the court verdict was "too little and too late".
Forty tonnes of a toxin called methyl isocyanate leaked from the Union Carbide pesticide factory and settled over slums in Bhopal on 3 December 1984.
The Indian government says some 3,500 people died within days and more than 15,000 in the years since.
Campaigners put the death toll as high as 25,000 and say the horrific effects of the gas continue to this day.
The site of the former pesticide plant is now abandoned.
It was taken over by the state government of Madhya Pradesh in 1998, but environmentalists say poison is still found there.
The eight convicted on Monday were Keshub Mahindra, the chairman of the Indian arm of the Union Carbide (UCIL); VP Gokhale, managing director; Kishore Kamdar, vice-president; J Mukund, works manager; SP Chowdhury, production manager; KV Shetty, plant superintendent; SI Qureshi, production assistant. All of them are Indians.
The seven former employees, some of whom are now in their 70s, were also ordered to pay fines of 100,000 Indian rupees (£1,467; $2,125) apiece.
Although Warren Anderson, the American then-chairman of the US-based Union Carbide parent group, was named as an accused and later declared an "absconder" by the court, he was not mentioned in Monday's verdict.
Rights groups and NGOs working with the victims of the gas leak said that the verdict was inadequate.
"It sets a very sad precedent. The disaster has been treated like a traffic accident. It is a judicial disaster, and it is a betrayal [of Indian people] by the government," activist Satinath Sarangi said.
Rashida Bee, president of the Bhopal Gas Women's Workers group, told the AFP news agency that "justice will be done in Bhopal only if individuals and corporations responsible are punished in an exemplary manner".
More than a dozen judges have heard the criminal case since 1987, when India's leading detective agency, the Central Bureau of Investigation (CBI), charged 12 people with "culpable homicide not amounting to murder".
That charge could have led to up to 10 years in prison for the accused.
However, in 1996, India's Supreme Court reduced the charges to "death by negligence", carrying a maximum sentence of up to two years in prison if convicted.
Campaigners say Bhopal has an unusually high incidence of children with birth defects and growth deficiency, as well as cancers, diabetes and other chronic illnesses.
These are seen not only among survivors of the gas leak but among people born many years later, they say.
Twenty years ago Union Carbide paid $470m (£282m) in compensation to the Indian government.
Dow Chemicals, which bought the company in 1999, says this settlement resolved all existing and future claims against the company.