The order on Kenyan and East Africa Community flags will remain in effect until Mr Nkurunziza is buried.

Local media has reported on the close friendship between President Kenyatta and the late Nkurunziza.

The Star newspaper quoted diplomatic sources as saying that the late president was to be flown to either Kenya's capital, Nairobi, or Tanzania's commercial hub, Dar es Salaam, for treatment.

Burundi first lady Denise Nkurunziza was being treated in Kenya when her husband's death was announced.

President Kenyatta on Tuesday sent his condolences to the first lady and the people of Burundi.
Caption: President Kenyatta (R) was among the first regional leaders to send condolences

Kenya's President Uhuru Kenyatta has ordered that flags be flown at half-mast across the country from Saturday in honour of the late Burundi President Pierre Nkurunziza.