(Adds background) PORT HARCOURT, Nigeria, Nov 7 (Reuters) - Gunmen in speedboats attacked the Nigerian military at an oil facility operated by U.S. energy firm Chevron <CVX.N> late on Thursday, killing one navy personnel, the military said on Friday. "Last night, some men in speedboats attacked our men at Robert-Kiri flow station. In the shoot-out there were fatalities. We lost one man, a naval personnel," said Lieutenant Colonel Sagir Musa, a miltary spokesman in the Niger Delta. "We do not know who is responsible for this," he said. Chevron was not immediately available for comment. Militants who say they are fighting for a fairer share of the wealth generated in the Niger Delta, home to Africa's biggest oil and gas industry, have bombed pipelines and oil platforms in recent years to push their demands. But the line between militancy and criminality is blurred. Networks of armed gangs have taken advantage of the breakdown in law and order to steal industrial quantities of crude oil -- known locally as "bunkering" -- part of an illegal international trade worth millions of dollars a day. Gunmen in speedboats trying to secure safe passage for crude oil thieves killed a civilian during a gun battle with the Nigerian security forces in the western Niger Delta late on Wednesday, the military said on Thursday. (Reporting by Austin Ekeinde; Writing by Nick Tattersall)
