of foreign oil workers , typically releasing them unharmed , sometimes after receiving a ransom payment . MEND hopes to secure a greater share of oil wealth for people in the delta , where more than 70 percent of the population lives on less than a dollar a day . Its attacks on oil facilities have taken a toll . `` Anytime a pipeline is affected , anytime any production gets shut down , you see oil prices jump up one or two dollars a barrel just because there is no slack in the system , '' said Jim LeCamp , a senior vice president with RBC Wealth Management , which manages assets for wealthy clients worldwide . Exxon and Shell are two of several companies that have been extracting 2 million barrels of oil a day in Nigeria . Recent rebel attacks on oil pipelines in the Niger Delta have cut overall production by roughly 10 percent -- meaning 200,000 fewer barrels of oil on some days . That decrease in production comes at a time of increased demand from oil-hungry regions such as China , Russia and Latin America . `` Anytime there 's a disruption there ,
LAGOS , Nigeria -LRB- CNN -RRB- -- Militants in Nigeria 's oil-rich southern delta region said they killed six government soldiers after the military attacked one of its camps on Thursday . Heavily armed Nigerian rebels pose a constant threat to oil pipelines in the country . The Movement for the Emancipation of the Niger Delta , in an e-mail , said three military gunboats attacked one of its camps around the Ke River in the country 's Rivers state . The group said the gunboats were repelled , with six soldiers dying and three militant fighters wounded in the skirmish . There was no immediate reaction from the government . Nigeria is Africa 's largest crude oil producer and the fourth-largest supplier of oil to the United States . MEND has demanded that more of the country 's oil wealth be pumped into the region instead of enriching foreign investors , and the militants have been attacking oil pipelines in retaliation against government forces , limiting the amount of crude oil that can leave the country . MEND -- the largest rebel group -- has targeted foreign oil companies since 2006 . It has bombed pipelines and kidnapped hundreds