Nigerian troops killed two assailants who were part of a group of gunmen that attacked an oil installation Thursday, the military said.
Soldiers also recovered three assault rifles from the militants, who attacked the pipeline interchange, said Lt. Col. Sagir Musa, a spokesman for the military task force charged with securing the restive southern Niger Delta.
Musa said two militants died in the attack. He gave no further details.
Royal Dutch Shell PLC only confirmed an incident involving staff of its local joint venture, saying gunmen attacked maintenance workers in the area, drawing a response from a nearby security patrol. Shell made no mention of attackers hitting the facility, or causing any damage.
The area's most potent militant group, the Movement for the Emancipation of the Niger Delta, said it had not authorized any attack on a so-called "flow station."
Overall violence is down from a year ago in Nigeria's southern region, residents say. But militants have stepped up their activities in the past few months as one of their supposed leaders is tried on terrorism and treason charges for allegedly trafficking in illegal weapons.
The militants have focused their efforts on sabotaging Nigeria's vast expanse of oil pipelines carrying crude oil from wells to central switching stations and onto export terminals.
Pipeline bombings in the last few months have cut oil production in Nigeria, Africa's biggest petroleum exporter. The drop in supplies and the unrest in Nigeria have contributed to the sharp rise in oil prices internationally.
The militants say they want the release of their leader and more federal government-controlled oil industry funds for their impoverished region, IHT reported.