Kenya's Nobel laureate Wangari Maathai has died in Nairobi while undergoing treatment for cancer. She was 71.
Ms Maathai won the Nobel Peace Prize in 2004 for promoting conservation, women's rights and transparent government - the first African woman to get the award.
She was elected as an MP in 2002 and served as a minister in the Kenyan government for a time, the BBC reports.
Ms Maathai founded the Green Belt Movement, which has planted 20 to 30 million trees in Africa.
The professor of veterinary anatomy rose to international fame for campaigns against government-backed forest clearances in Kenya in the late 1980s and 90s.
Under the former government of President Daniel Arap Moi, she was arrested several times and vilified.
In 2008, Ms Maathai was tear-gassed during a protest against the Kenyan president's plan to increase the number of ministers in the cabinet.
In her speech accepting the Nobel prize, Ms Maathai said she hoped her own success would spur other women on to a more active role in the community.