Kenya has denied its athletes clearance to compete at the Kilimanjaro Marathon in Tanzania over concerns about the Covid-19 pandemic.
The IAAF-recognised race will be held early Sunday morning at the foot of Mount Kilimanjaro, the tallest mountain in Africa.
Kenyan athletes have dominated previous editions of the race.
In a statement, Athletics Kenya urged "all athletes not to travel to Tanzania for the event".
Tanzania has not been sharing data on the coronavirus situation in the country and until recently had been downplaying the pandemic.
The World Health Organization early this week urged Tanzania to start reporting coronavirus cases and share its data.