The burnt wreckage of two Ugandan army helicopters was found Tuesday, two days after crashing in a remote mountainous region of Kenya while flying to war-torn Somalia, army officials said.

"The aircraft have been found but they are all burnt," a senior Kenyan military official said. "We do not know the fate of the crew."

Kenyan army spokesman Bogita Ongeri confirmed the aircraft had been found.

"The helicopters were sighted by a fixed-wing aircraft somewhere around Mount Kenya," Ongeri said, adding that officials would release more information later in the day. "The rescue efforts are ongoing."

There was no news of the reported 10 servicemen onboard the two helicopters.

A third helicopter on the same mission also crashed in forests in the Mount Kenya region late Sunday, but all seven Ugandan servicemen onboard were rescued on Monday, after they managed to radio for help.

The three Russian-made Mi-24 combat helicopters were flying to Somalia to support African Union troops battling Al-Qaeda-linked Shebab insurgents, who have vowed to topple the country's Western-backed government.

The aircraft came down in thickly forested mountainous terrain dominated by snowcapped Mount Kenya, Africa's second-highest peak at 5,199 metres (17,057 feet).

Wild animals including elephants, leopards and rhinos prowl the forests, about 110 kilometres (70 miles) north of the capital Nairobi.

A Mi-17 transport helicopter which had taken off from Uganda on Sunday as part of the same mission landed without problems in the eastern Kenyan town of Garissa near the Somali border for a scheduled refueling stop.

Uganda provides around a third of the nearly 17,000-strong AU force in Somalia, and Kampala had said last week it would send its first combat and transport helicopters to the Horn of Africa nation.

The aircraft are seen as key to extending gains made against the hardline Shebab insurgents, who have fled a string of stronghold towns in recent months, stretching AU military resources over a far wider zone.