Instructors from the Ujamaa self-defence programme train a group of women to protect themselves against rape at the Mukuru Kwa Njenga slum in the capital Nairobi, Kenya, March 16, 2015. Across Nairobi, more than 200 elderly women, aged up to 105, are learning self defence to protect themselves against rape, which is widespread in Kenya, particularly in its slums. Research by the charity Ujamaa, which runs the self defence programme, shows that one in four women in Korogocho experience sexual assault. Picture taken March 16, 2015. To match Thomson Reuters Foundation story KENYA-RAPE/GRANNIES REUTERS/Siegfried Modola

Instructors from the Ujamaa self-defence programme train a group of women to protect themselves against rape at the Mukuru Kwa Njenga slum in the capital Nairobi, Kenya, March 16, 2015. Across Nairobi, more than 200 elderly women, aged up to 105, are learning self defence to protect themselves against rape, which is widespread in Kenya, particularly in its slums. Research by the charity Ujamaa, which runs the self defence programme, shows that one in four women in Korogocho experience sexual assault. Picture taken March 16, 2015. To match Thomson Reuters Foundation story KENYA-RAPE/GRANNIES REUTERS/Siegfried Modola? TPX IMAGES OF THE DAY

An instructor from the Ujamaa self-defence programme trains a group of women to protect themselves against rape at the Mukuru Kwa Njenga slum in the capital Nairobi, Kenya, March 16, 2015. Across Nairobi, more than 200 elderly women, aged up to 105, are learning self defence to protect themselves against rape, which is widespread in Kenya, particularly in its slums. Research by the charity Ujamaa, which runs the self defence programme, shows that one in four women in Korogocho experience sexual assault. Picture taken March 16, 2015. To match Thomson Reuters Foundation story KENYA-RAPE/GRANNIES REUTERS/Siegfried Modola

Instructors from the Ujamaa self-defence programme train a group of women to protect themselves against rape at the Mukuru Kwa Njenga slum in the capital Nairobi, Kenya, March 16, 2015. Across Nairobi, more than 200 elderly women, aged up to 105, are learning self defence to protect themselves against rape, which is widespread in Kenya, particularly in its slums. Research by the charity Ujamaa, which runs the self defence programme, shows that one in four women in Korogocho experience sexual assault. Picture taken March 16, 2015. To match Thomson Reuters Foundation story KENYA-RAPE/GRANNIES REUTERS/Siegfried Modola

Mary Njoki Wainaina, 85, prepares herself for the day's work, in her home in the slum of Korogocho in the capital Nairobi, Kenya, March 17, 2015. Across Nairobi, more than 200 elderly women, aged up to 105, are learning self defence to protect themselves against rape, which is widespread in Kenya, particularly in its slums. Research by the charity Ujamaa, which runs the self defence programme, shows that one in four women in Korogocho experience sexual assault. Wainaina collects waste plastics on a dump site and sells them for recycling, a job she has been doing since her husband died 30 years ago. She has been attending the class for four years and shares her knowledge with her five-year-old granddaughter, who she lives with. Picture taken March 17, 2015. To match Thomson Reuters Foundation story KENYA-RAPE/GRANNIES REUTERS/Siegfried Modola

A woman walks on a street at the Mukuru Kwa Njenga slum in the capital Nairobi, Kenya, March 16, 2015. Across Nairobi, more than 200 elderly women, aged up to 105, are learning self defence to protect themselves against rape, which is widespread in Kenya, particularly in its slums. Research by the charity Ujamaa, which runs the self defence programme, shows that one in four women in Korogocho experience sexual assault. Picture taken March 16, 2015. To match Thomson Reuters Foundation story KENYA-RAPE/GRANNIES REUTERS/Siegfried Modola

Mary Njoki Wainaina, 85, makes her way to the Dondora dumpsite close to the slum of Korogocho to start her day's work foraging for recycling material among the rubbish, in the capital Nairobi, Kenya, March 17, 2015. Across Nairobi, more than 200 elderly women, aged up to 105, are learning self defence to protect themselves against rape, which is widespread in Kenya, particularly in its slums. Research by the charity Ujamaa, which runs the self defence programme, shows that one in four women in Korogocho experience sexual assault. Wainaina collects waste plastics on a dump site and sells them for recycling, a job she has been doing since her husband died 30 years ago. She has been attending the class for four years and shares her knowledge with her five-year-old granddaughter, who she lives with. Picture taken March 17, 2015. To match Thomson Reuters Foundation story KENYA-RAPE/GRANNIES REUTERS/Siegfried Modola

Mary Njoki Wainaina, 85, forages for recycling material among rubbish at the Dondora dumpsite close to the slum of Korogocho in the capital Nairobi, Kenya, March 17, 2015. More than 200 elderly women across the city, aged up to 105, are learning self-defence to protect themselves against rape, which is widespread across Kenya, particularly in its crime-ridden slums. Research by the charity Ujamaa, which runs the programme, shows that one in four women in Korogocho experience sexual assault. The programme is expanding, with seven classes across the city, up from two in 2012. Wainaina has been attending the class for four years and shares her knowledge with her five-year-old granddaughter, who she lives with. To match story KENYA-RAPE/GRANNIES Picture taken on March 17, 2015. REUTERS/Siegfried Modola

An elderly woman attends a class run by the Ujamaa self-defence programme teaching women how to protect themselves against rape in the Korogocho slum in the capital Nairobi, Kenya, April 23, 2015. More than 200 elderly women across the city, aged up to 105, are learning self-defence to protect themselves against rape, which is widespread across Kenya, particularly in its crime-ridden slums. Research by the charity Ujamaa, which runs the programme, shows that one in four women in Korogocho experience sexual assault. The programme is expanding, with seven classes across the city, up from two in 2012. To match story KENYA-RAPE/GRANNIES Picture taken on April 23, 2015. REUTERS/Siegfried Modola

Mary Njoki Wainaina, 85, forages for recycling material among rubbish at the Dondora dumpsite close to the slum of Korogocho in the capital Nairobi, Kenya, March 17, 2015. Across Nairobi, more than 200 elderly women, aged up to 105, are learning self defence to protect themselves against rape, which is widespread in Kenya, particularly in its slums. Research by the charity Ujamaa, which runs the self defence programme, shows that one in four women in Korogocho experience sexual assault. Wainaina collects waste plastics on a dump site and sells them for recycling, a job she has been doing since her husband died 30 years ago. She has been attending the class for four years and shares her knowledge with her five-year-old granddaughter, who she lives with. Picture taken March 17, 2015. To match Thomson Reuters Foundation story KENYA-RAPE/GRANNIES REUTERS/Siegfried Modola

Elderly women attend a class run by the Ujamaa self-defence programme teaching women how to protect themselves against rape in the Korogocho slum in the capital Nairobi, Kenya, April 23, 2015. More than 200 elderly women across the city, aged up to 105, are learning self-defence to protect themselves against rape, which is widespread across Kenya, particularly in its crime-ridden slums. Research by the charity Ujamaa, which runs the programme, shows that one in four women in Korogocho experience sexual assault. The programme is expanding, with seven classes across the city, up from two in 2012. To match story KENYA-RAPE/GRANNIES Picture taken on April 23, 2015. REUTERS/Siegfried Modola