A rights group alleges that corrupt Kenyan wildlife rangers are killing poachers to cover up the officers' collusion with the gangs slaughtering the country's elephants.

Muslims for Human Rights documented the disappearances and extrajudicial killings of 18 suspected poachers over the last three years around Kenya's Tsavo National Park, a wildlife sanctuary that had 25,000 elephants in the 1970s but which has only 11,000 today.

Francis Auma, an official with the Muslim rights group, said the victims — many of whom are ethnic Somalis — were often last seen in the custody of Kenya Wildlife Service officers. He said their bodies were later discovered in forests after being eaten by animals.

The report says the rangers committed the murders to cover up their involvement with the poachers in killing elephants.