JAKARTA, Indonesia — The forest fire and haze disaster in Southeast Asia last year may have led to the deaths of more than 100,000 people, according to a study released Monday by researchers from two United States universities. A vast majority of the cases were in Indonesia, where fires were deliberately set to clear land for agriculture.

The study, led by experts in public health and atmospheric modeling from Harvard and Columbia, estimated that 91,600 people in Indonesia, 6,500 in Malaysia and 2,200 in Singapore may have died prematurely because of exposure to fine particle pollution from burning forests, in particular carbon-rich peatlands.

The study said those figures were nearly 2.7 times higher than the 37,600 estimated deaths in the three countries because of exposure to fine particles during a fire and haze crisis in 2006.

The particles, known as PM 2.5 because they are 2.5 micrometers in diameter or smaller, are also typical in diesel emissions, among other things. When inhaled, they can cause severe health problems, including asthma, bronchitis, lung cancer and cardiovascular disease.