Two Australians killed in Kenya crash

Two Australians are dead after a tourist bus rolled and crashed into a river on a notorious stretch of road in Kenya.

Initial reports said an elderly Australian woman had died at the scene and 25 other people, including 14 Australians, had been taken to hospital with injuries including fractures and head wounds.

The number of Australians killed has now risen to two, with Prime Minister Tony Abbott confirming consular officials in Nairobi are assisting the families of the dead and injured.

"It's awful beyond belief for the families of all of those involved," Mr Abbott said on Monday.

Four of the injured have since been released from hospital.

The bus, which was taking the group to the popular Masai Mara game reserve, overturned outside Nairobi on Sunday night, rolling down a steep embankment and landing on its roof in a shallow river.

It's believed the crash occurred after a tyre burst.