Two of about a dozen armed attackers who invaded an oil facility owned by a subsidiary of Anglo-Dutch Shell in Nigeria's southern Bayelsa State were shot dead on Wednesday by naval officers, police said.
"Two of them were shot dead by naval officers while one other was arrested alive. He is currently undergoing investigation," Bayelsa Police Commissioner Hafiz Ringim told AFP by telephone.
A Shell spokesman confirmed the attack but said it was immediately repelled by security forces.
"Indeed there was an attack today (Wednesday) on a workers' residential area near Nun River in Oporoma by an armed gang. There were a lot of security men around and they repelled the attack. It did not in any way affect our production," said the official, who declined to be named.
"We were at alert, considering previous attacks on our facilities by gunmen. So this particular attack did not succeed," he added.
Shell later issued a formal statement on the attack.
The "SPDC (Shell Petroleum Development Company) has received reports of an attack on its Nun River Field Logistics Base in early hours of today (Wednesday). We have no indication of the identity of the attackers or damage or injuries.
"Staff had been evacuated from the field logistics base following an attack by militants," said the statement signed by Diezani Alison-Madueke, the company's director of external affairs.
This is the second reported attack on a Shell facility in Oporoma in five weeks.
Around 60 Nigerian employees of Shell and contract personnel were taken hostage by armed men October 10 in a Shell facility in the Oporoma community.
Scores of armed youths, protesting the alleged non-implementation of a Shell accord with the local community, then invaded a flowstation on Nun River in Oporoma, forcing the closure of the facility and causing a loss of 12,000 barrels of oil per day.
The hostages were released within 72 hours after talks between representatives of the youths, the government and Shell officials.
Last on Saturday, unidentified gunmen stole three speedboats from a pumping station operated by Italian oil company Agip in southern Nigeria's restive Niger Delta region.
The armed men stole the boats from the Clough Creek flow station in the southern Bayelsa state. That incident occurred as another Agip flowstation in Bayelsa state, Tebidaba, was occupied by the armed protestors who invaded it on November 6.
Attacks on oil installations, kidnappings of foreigners and sometimes killings of Nigerian oil workers, are carried out by armed groups that claim to be seeking a larger share of the country's oil wealth and jobs for the local community.
Since January, separatists and armed groups seeking benefits from the oil wealth for the Delta's 14-million strong ethnic Ijaw community have been blamed for a spate of violent attacks on multinational oil firms and their staff.
Nigeria, Africa's largest oil producer and the world's sixth oil producer, derives more than 95 percent of its foreign exchange earnings from oil.