Wild chimps have been known to attack and eat people in Nigeria, so this latest should come as no surprise. I recall a story from Nigeria last winter where a group of American researchers were driving by taxi into a wildlife preserve. I don't recall if the Taxi broke down, or if they were just taking a piss-break, but the group was attacked by a band of chimpanzees and their driver was killed and presumably eaten. The researchers escaped, but with an undetermined number of wounds.
I for one wouldn't want to go into chimp country unless I was part of a heavily armed group.