Militants claim to have overpowered gunboat and bombed a major pipeline . Score: 6 The recent violence -- which has included attacks on pipelines and hostage-taking -- has limited shipment of crude oil supplies out of Nigeria , Africa 's largest producer . Last month the militant group declared an `` all-out war '' on the government . Recent violence has limited shipments of crude oil supplies from Nigeria .
Militants claim to have overpowered gunboat and bombed a major pipeline . Score: 6 Last month the militant group declared an `` all-out war '' on the government . Recent violence has limited shipments of crude oil supplies from Nigeria .