Nigerian militants on Tuesday bombed a state-run oil pipeline near the southern port city of Warri, the second attack within a week, a community leader and army officer said.
"The line which was undergoing repair after the previous attack ... was billed for commissioning either today or tomorrow," before the latest attack, chairman of Batan community Dickson Ogugu told AFP.
He said four surveillance guards deployed to protect the Trans Forcados export line narrowly escaped death after the militants opened fire on them.
"The hoodlums after chasing them from the spot came down from their speedboat, planted dynamite on swamp boogie, barge, crane and on the line," he said.
"Unfortunately, only the dynamite on the barge exploded and immediately sank into the water. As I speak to you, the military are at the scene of the incident trying to dismantle the other dynamites."
An army officer, who did not want to be named, confirmed the incident.
"We heard the shots in the middle of the night, but as you know, we do not patrol the area at night, so there was nothing we could do," he said.
The line has been previously targeted by rebels.
Last week, the line was bombed just hours after President Muhammadu Buhari met with representatives of militant groups in the Niger delta to discuss how to end the unrest wracking the region.
The state-owned Pipelines and Product Marketing Company (PPMC) operates the pipeline which receives crude from the Batan flowstation and feeds the Forcados export terminal.
Since the start of the year, several militant groups have attacked oil facilities, slashing the nation's output and hammering revenues.
The militants claim to be seeking a fair share of the nation's oil wealth for local residents as well as political autonomy for the region.
The government has launched peace talks with the rebels to end the violence.