"The Russian-Chechen conflict ... marks a return to totalitarianism," Interfax quoted her as saying in an appeal to Yeltsin.
"No idea, including the idea of Russia's unity -- which is close to many Russians' hearts -- can justify a war against the people," she was quoted as saying.
Bonner could not reached by telephone to confirm the report.
Sakharov, who died in 1989, abandoned the Soviet establishment in 1968 when forces of the Soviet-led Warsaw Pact invaded Czechoslovakia. He became a campaigner for human rights, and was awarded the Nobel Peace Prize in 1975.
Bonner was sharply critical of Yeltsin, who has said the troops are in Chechnya to defend Russian integrity and restore constitutional order.
"Russian soldiers are defending primarily the interests of the military-industrial complex, the army leadership connected with it, and domestic oil tycoons," Bonner said.
"A democratic country cannot put a military stranglehold on a people that does not want to remain part of it."
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