OSLO, Norway - Kenyan environmental activist Wangari Maathai won the Nobel Peace Prize today for her work as leader of the Green Belt Movement, which has sought to empower women, improve the environment and fight corruption in Africa for almost 30 years.

Maathai, Kenya's deputy environment minister, is the first African woman to win the prize, first awarded in 1901. She gained recent acclaim for a campaign planting 30 million trees to stave off deforestation.

"We believe that Maathai is a strong voice speaking for the best forces in Africa to promote peace and good living conditions on that continent," the Nobel committee said in its citation.

Maathai said she thought she was selected as a symbol of the struggles against poverty and environmental degradation in Africa.

"This is an overwhelming experience. It is elating. It is unbelievable, it's the kind of thing you never hear in your life. I am very flattered," she told The Associated Press in Nyeri, Kenya.

With a record 194 nominations, the committee had a broad field to choose from, and speculation had focused on other candidates. Many observers had wondered if the committee would try to send a message about Iraq, as it did in 2002, when members said the choice of former U.S. President Jimmy Carter should be seen as criticism of the Bush administration's move to topple Saddam Hussein.

The choice of Maathai was a clear answer that it would eschew politics this time around.

It was the first time the prize recognized work to preserve the environment. During the 2001 centennial anniversary of the prize, the committee said it wanted to widen the scope of the award, including honoring those who worked to improve the environment, as well as contributed to advancing peace worldwide.

"This is the first time environment sets the agenda for the Nobel Peace Prize, and we have added a new dimension to peace. We want to work for a better life environment in Africa," said committee chairman Ole Danbolt Mjoes.

Maathai, 64, is believed to have been the first woman in East and Central Africa to earn a doctorate. She got a degree in biological sciences from Mount St. Scholastica College in Atchison, Kan., in 1964.