Ethiopia Airlines is examining the reasons why a Boeing 767-300 registered to the carrier landed at the small Tanzanian airport of Arusha.
Flight ET815 had been due to arrive at Kilimanjaro, following a service from Addis Ababa, but was unable to land.
Ethiopian says a "crippled Cessna" on the runway forced the diversion. "Hence the aircraft landed at an alternate airport," the carrier states.
But it has yet to explain why the 767 diverted to such a small facility. Nairobi's international airport is about 250km north of Kilimanjaro.
Arusha is about 50km west of Kilimanjaro airport. Both have single runways aligned east-west, designated 09/27, but Kilimanjaro’s runway, at just over 3,600m, is twice the length of Arusha’s.
Images from social media at the incident site indicate the aircraft is ET-AQW, a 24-year old airframe powered by Pratt & Whitney PW4000 engines.
They also show that the aircraft has come to rest with its nose-gear in soft ground. Ethiopian says the aircraft's nose-gear "went slightly off the runway" but all passengers and crew disembarked safely.
Neither Kilimanjaro nor Arusha airport appears to have issued NOTAM data which might clarify the situation.