Mary Travers, the female third of the wildly popular folk trio Peter, Paul and Mary, whose anthems lent passionate voice to the 1960s protest movement, died on Wednesday after battling leukemia, her publicist said. She was 72.

"She passed away today at Danbury hospital in Danbury, Connecticut," Heather Lylis told AFP.

Travers and her fellow bandmates, Peter Yarrow and Noel "Paul" Stookey, burst onto the American folk music scene in 1961 with an influential style punctuated by rich three-part harmonies and activist politics.

The honey-voiced singer with signature blonde bangs emerged from the coffeehouses of New York's Greenwich Village and, flanked by her two male guitarist companions, stepped into superstardom with a string of hits including their version of If I Had a Hammer, their singalong anthem about racial equality, as well as the single Lemon Tree, the anti-war ballad Where Have All the Flowers Gone? and the whimsical Puff the Magic Dragon.

Despite their folk roots, the band quickly achieved commercial success, with their self-titled 1962 debut record reaching number one on the US charts and selling more than two million copies.

Their spruced up version of Blowin' in the Wind became a popular interpretation of fellow folk singer Bob Dylan's anti-war anthem, and Peter, Paul and Mary performed the song at the 1963 civil rights March on Washington.

In 1969, their cover of the John Denver song Leaving On A Jet Plane became their only No 1 single. The trio broke up in 1970 to pursue solo careers, but never matched the success they enjoyed as a band.

Travers dived into activist work, speaking out about the challenges facing Russian "Refusnik" Jews whose applications to emigrate from the Soviet Union were denied, in support of human rights in Central America, and against South African Apartheid.

The trio reunited often for concerts, but took a pause when Travers was diagnosed with cancer in 2004.

She eventually had a bone marrow transplant, side effects of which contributed to her death, Lylis said.

But not before reuniting for several tours that saw the group play dozens of concerts in recent years, including their final performance together in May 2009 in New Jersey, according to Lylis.