MOSCOW: Yelena Bonner, a relentless critic of human rights abuses by Soviet-era authorities and the widow of Nobel Peace laureate Andrei Sakharov, has died at the age of 88, her children said. Bonner continued to advocate rights and democracy in post-communist Russia and was outspoken against Prime Minister Vladimir Putin. She died Saturday in the United States, where she had lived in recent years in the Boston area, her daughter Tatiana Yankelevich and son Alexey Semyonov said in a statement posted on the website of the Andrei Sakharov Foundation. It did not give the cause of death. Her children said her memorial service would be held on Tuesday in Brookline, Massachusetts.