Caterpillar, Volvo and Komatsu contribute to abuses in Myanmar by selling machinery used by domestic mining companies implicated in land expropriation, environmental destruction and armed conflict, according to a report published on Wednesday.
The three companies "appear to be the dominant brands" represented in the Hpakant jade mines in northern Myanmar's Kachin state, according to Swedwatch, a Stockholm-based charity.
The research suggested thousands of people had lost their land in the past 15 years, while hundreds may have died each year in landslides and flooding linked to the mines.