(Adds militant groups' reaction, new throughout) By Austin Ekeinde PORT HARCOURT, Nigeria, Aug 15 (Reuters) - Twelve Nigerian militants and a naval officer were killed in a gunbattle on Friday near a Royal Dutch Shell <RDSa.L> natural gas plant in the oil-producing Niger Delta, military and security sources said. Lieutenant Colonel Sagir Musa, spokesman for the military task force in southern Rivers state, said militants ambushed two navy gunboats on patrol in Rivers state. The Shell-operated gas plant did not come under fire. "This evening our men of the (Joint Task Force) came under attack around Alakiri on the Port Harcourt-Bonny sea route," said Musa. "We responded and exchanged fire and we killed several of the militants." Two security sources said at least 12 militants and one soldier were killed in the fighting. The Movement for the Emancipation of the Niger Delta (MEND), which launched a campaign of violence against the oil sector in early 2006, dismissed the high casualty report. "No MEND units or affiliated groups have reported such heavy losses," the militant group said in an e-mailed statement. Militant attacks on Nigeria's oil facilities have become increasingly frequent, shutting down a fifth of oil production in the last two years. The Niger Delta Vigilante, a militant group with links to MEND, threatened more violence in the area. "We are by this notice asking all oil companies and foreigners to leave Port Harcourt because there is no going back," said the group's spokesman, who uses the pseudonym Tamunokuro Ebitari. "We are bringing the fight to their door post and we will not spare anybody or companies," he added. The militant group said on Monday that its "diving unit" had attacked a pipeline owned by state-oil firm NNPC that supplies natural gas to the Alakiri flow station. Officials with Nigeria's Joint Task Force, NNPC and Shell could not confirm the attack. Various armed groups operate under the franchise of MEND, which says it is fighting for greater control of the region's oil resources. (Writing by Randy Fabi; editing by Tim Pearce)
U.N. peacekeepers from Nigeria stand guard during a demonstration by supporters of Haiti's former president Jean Bertrand Aristide, demanding his return, in front of the National palace in Port-au-Prince July 15, ...
