In July 1969, Mboya—a prominent and popular Luo KANU politician—was assassinated by a Kikuyu. Kenyatta had reportedly been concerned that Mboya, with U.S. backing, could remove him from the presidency, and across Kenya there were suspicions voiced that Kenyatta's government was responsible for Mboya's death. The killing sparked tensions between the Kikuyu and other ethnic groups across the country, with riots breaking out in Nairobi. In October 1969, Kenyatta visited Kisumu, located in Luo territory, to open a hospital. On being greeted by a crowd shouting KPU slogans, he lost his temper. When members of the crowd started throwing stones, Kenyatta's bodyguards opened fire on them, killing and wounding several. In response to the rise of KPU, Kenyatta had introduced oathing, a Kikuyu cultural tradition in which individuals came to Gatundu to swear their loyalty to him. Journalists were discouraged from reporting on the oathing system, and several were deported when they tried to do so. Many Kenyans were pressured or forced to swear oaths, something condemned by the country's Christian establishment. In response to the growing condemnation, the oathing was terminated in September 1969, and Kenyatta invited leaders from other ethnic groups to a meeting in Gatundu.