The tribal strife in the oil producing regions is becoming increasingly disruptive. Today, members of the Warri tribe seized a pumping station and cut off the flow of millions of dollars a day worth of oil. Some 90 percent of Nigeria's export earnings are from oil. The Warri are constantly feuding with the Itsekiri and Urhobo over who gets what from the oil business. These efforts often amount to extortion and in many cases are just a matter of one upmanship over the other tribes.