NAIROBI (Reuters) - Unidentified gunmen killed a senior United Nations aid worker in remote northwestern Kenya, the U.N. World Food Programme said on Friday.

Silence Chirara, a 37-year-old Zimbabwean, was the WFP logistics coordinator for southern Sudan. He was ambushed late on Wednesday as he drove near a U.N. camp in Lokichoggio, the main humanitarian operations hub for south Sudan.

The WFP said it was the first killing of a staff member there.

"We are all shocked at this savage killing and condemn it in the strongest terms. U.N. security and the Kenyan police are investigating this terrible crime," the WFP representative in Sudan, Kenro Oshidari, said in a statement.

During Sudan's long north-south civil war, WFP planes operating out of Lokichoggio airdropped food aid to millions of people in southern Sudan.

Since the war ended three years ago, the town has remained an important relief hub and access route for aircraft and trucks taking relief supplies into Sudan.

WFP said Chirara, who joined the organisation in 1996, had worked in Iraq, Guinea Bissau, Zimbabwe and Indonesia. It said he began working in Lokichoggio in March 2006.