Zimbabwe's main opposition leader and President Robert Mugabe's chief rival for the last 17 years said on Tuesday he has been diagnosed with cancer of the colon and is undergoing treatment in neighbouring South Africa.
Morgan Tsvangirai, 64, who was Zimbabwe's prime minister in an uneasy coalition government with the 92-year-old Mugabe from 2009 until 2013, said it was important for national leaders to disclose their health status.