The Associated Press reports gunmen attacked a Chevron Corp. crude oil pipeline that runs through the Niger Delta. The pipeline transports crude oil out of Chevron''s seven swamp fields in the area. Chevron spokesman Scott Walker said workers stopped the pipeline flow, holding back about 20,000 barrels. Chevron Nigeria Ltd., the company''s local subsidiary, operates the line with the state-run Nigerian National Petroleum Corp. Chevron. The Chevron subsidiary "is assessing the situation, has informed relevant stakeholders including the communities and is committed to the safety and security of its employees and the protection of the environment in all its operations,"