A search is under way in Kenya for two Ugandan military helicopters which have gone missing.
The helicopters were among four which were due to make a stop in the Kenyan town of Wajir, but only one did so.
A Kenyan defence department spokesman told the BBC a pilot of another of the helicopters has contacted the department from Mount Kenya.
The aircraft were part of a contingent being sent to reinforce the African Union peacekeeping force in Somalia.
It was not known whether the helicopter of the pilot who contacted Kenyan defence officials had crashed or had landed safely, Kenyan defence department spokesman Bogita Ongeri said.
The Kenyan army has launched a land and air rescue operation but it is being hampered by bad weather, Mr Ongeri added.
It is not clear exactly how many people were on board the helicopters.
"The search is going on, we don't know what exactly happened but we are investigating it," Ugandan military spokesman Felix Kulayigye had said.
Ugandan troops are part of the African Union force fighting the Somali Islamist group al-Shabab, which pledges loyalty to al-Qaeda.
The force has been planning to launch an "onslaught" against al-Shabab in the Somali port of Kismayo later this month.