Kenyan emergency teams searched for a third day Wednesday for five personnel still unaccounted for after three Ugandan military helicopters crashed at the weekend, officials said.

"Search and rescue operations are underway and our teams are on the mountain," said Simon Gitau, a senior warden with the Kenya Wildlife Service, which is assisting in the rescue operations.

The Russian-made Mi-24 combat helicopters went down in a remote mountain region, near snowcapped Mount Kenya, on Sunday while en route to support African Union troops in war-torn Somalia.

One helicopter was found on Monday, with all seven servicemen on board rescued. The wreckage of the two other aircraft was found Tuesday, with one aircraft badly burned.

Two bodies were found in the charred wreck of one, but eight survivors from the other aircraft trekked eight kilometres (five miles) through dense forests in search of help, and were airlifted to Nairobi on Tuesday.

On Wednesday Kenyan army spokesman Bogita Ongeri said, "We are looking for five more people.

The Ugandan army said in a statement: "Our hearts are with those family members whose dear ones we are still searching for."

The aircraft came down in thickly forested mountainous terrain dominated by 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.

Uganda, which has blamed poor weather for the crashes, provides around a third of the nearly 17,000-strong AU force in Somalia.

Kampala had said last week that it would send its first combat and transport helicopters to the Horn of Africa nation.

The aircraft were 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.