An opposition supporter gestures with a knife during clashes with police in Kibera slum in Nairobi, Kenya on October 26, 2017. Kenyans trickled into polling stations today for a repeat election that has polarised the nation, amid sporadic clashes as supporters of opposition leader ignored his call to stay away and tried to block voting. (Photo by Goran Tomasevic/Reuters)

A schoolgirl runs past a burning barricade in Kibera slum, Nairobi on May 23, 2016 during a demonstration of opposition supporters protesting for a change of leadership ahead of a vote due next years. (Photo by Carl De Souza/AFP Photo)

Camel herders scoop up water in plastic buckets from one of the few watering holes in the area, to water their animals near the drought-affected village of Bandarero, near Moyale town on the Ethiopian border, in northern Kenya, Friday, March 3, 2017. The U.N. humanitarian chief, Stephen O'Brien, toured Bandarero village on Friday and called on the international community to act to “avert the very worst of the effects of drought and to avert a famine to make sure we don't go from what is deep suffering to a catastrophe”. (Photo by Ben Curtis/AP Photo)

Young Turkana tribeswomen sing in a village near Baragoy, Kenya August 6, 2017. Kenyans are due to go to the polls on Aug. 8. to vote in presidential elections after a tightly-fought race between President Uhuru Kenyatta and main opposition leader Raila Odinga. (Photo by Goran Tomasevic/Reuters)

A protester holds a poster displaying the message “Get away UK” during an anti-British demonstration in the Iranian capital that resulted in a break in at the British Embassy on November 29, 2011 in Tehran, Iran. (Photo by FarsNews/Getty Images)

A Maasai man in ceremonial dress poses for visitors to take photographs of him in front of one of around a dozen pyres of ivory, in Nairobi National Park, Kenya Thursday, April 28, 2016. The Kenya Wildlife Service (KWS) has stacked 105 tons of ivory consisting of 16,000 tusks, and 1 ton of rhino horn, from stockpiles around the country, in preparation for it to be torched on Saturday to encourage global efforts to help stop the poaching of elephants and rhinos. (Photo by Ben Curtis/AP Photo)

A wildlife ranger strokes a northern white rhino, only three of its kind left in the world, ahead of the Giant Club Summit of African leaders and others on tackling poaching of elephants and rhinos, Ol Pejeta conservancy near the town of Nanyuki, Laikipia County, Kenya, April 28, 2016. (Photo by Siegfried Modola/Reuters)

A man walks in the early morning to start his day picking tea leaves at a plantation in Nandi Hills, in Kenya's highlands region west of capital Nairobi, November 5, 2014. Emerald-coloured tea bushes blanketing the rolling hills of Nandi County have long provided a livelihood for small-scale farmers, helping make Kenya one of the world's biggest tea exporters. But ideal weather and bigger harvests, instead of producing bumper earnings, have led to a glut of Kenya's speciality black tea. (Photo by Noor Khamis/Reuters)