A third helicopter on the same mission made an emergency landing in Mount Kenya on Sunday.

Its passengers have been rescued, Kenyan army spokesman Col Cyrus Oguna said.

Only one of the four Russian-made helicopters en route to Somalia made a scheduled refuelling stop on Sunday in the Kenyan town of Garissa.

The wreckage of the two missing helicopters was spotted on Mount Kenya - Africa's second-highest peak at 5,199 metres (17,057 feet) - by wildlife officers.

The deputy warden of Mount Kenya National Park, Simon Gitau, said rescue workers saw two bodies and helped rescue five other people from one of the two downed helicopters, the AP news agency reports.

One helicopter has been completely destroyed and the other partially, Col Oguna told the BBC.

The combat helicopters came down as they were flying from Uganda to Somalia to take part in an AU-led offensive to capture the port city of Kismayo from the militant Islamist group al-Shabab, correspondents say.

Ugandan troops form the bulk of the nearly 17,000-strong AU force in Somalia, where they are supporting the UN-backed government.

Although it has lost ground in the past year, al-Shabab, which has joined al-Qaeda, still controls many southern and central areas.