The United Nations World Food Program (WFP) says the head of its office in northwest Kenya has been ambushed and killed.

In a statement Friday, the WFP says Silence Chirara was gunned down late Wednesday near the U.N. camp in Lokichoggio by unidentified gunmen, who then fled.

The statement says at the time, Chirara was driving a clearly marked U.N. vehicle and was just 100 meters from the camp's main gate.

Chirara was the coordinator of the WFP's logistics operation for southern Sudan.  The WFP's representative in Sudan, Kenro Oshidari, condemned what he called a "savage" killing, and said U.N. security and Kenyan police are investigating.

This was the first killing of a WFP aid worker in Lokichoggio, a major hub for relief efforts in southern Sudan.

Chirara, a Zimbabwean national, was the second WFP worker killed in eastern Africa this week.

The agency said one of its truck drivers was shot and killed Wednesday at an illegal checkpoint in central Somalia.

Some information for this report was provided by AFP, AP and Reuters.