Gunmen shot and wounded Italian-born conservationist Kuki Gallmann at her conservation park in northern Kenya on Sunday, a source close to her family said.
The 73-year-old author of the memoir "I Dreamed of Africa" was shot in the stomach after the vehicle she was driving in was ambushed by a group of gunmen, the source said.
Gallmann was first flown by helicopter to Nanyuki Hospital where she received treatment but was later transferred to another hospital in Kenya's capital, Nairobi.
A wave of violence has hit Kenya's drought-stricken Laikipia region in recent months as armed cattle-herders searching for scarce grazing land have driven tens of thousands of cattle onto private farms and ranches from poor quality communal land.
At least 14 people have been killed.
Some local Kenyan farmers have also been attacked and had their livestock stolen.
The source also told Reuters a local Kenyan, Duncan Murimi, was shot in the stomach by militias from the local Pokot tribe and died three days ago in the same area.
The militias stole nothing from him and had no cattle looking for grass when they attacked him.
Last month, Tristan Voorspuy, a British military veteran who ran a safari company in Kenya, was shot dead at a private ranch in Laikipia.
He had gone to the ranch to inspect the remains of a friend's home that had been burnt down by herders days earlier
