By Felix Onuah
ABUJA (Reuters) - Nigeria's President Muhammadu Buhari on Friday said he had ordered a heightened military presence in the restive Niger Delta region to deal with a resurgence of militant attacks on oil and gas facilities.
The rise in attacks in the oil-rich southern region in the last few weeks have driven Nigerian oil output to a more than 20-year low.
A group calling itself the Niger Delta Avengers has claimed responsibility for most of them.
Speaking at a meeting with a Shell executive who oversees the energy giant's global upstream operations, Buhari said he had instructed the chief of naval staff to reorganize and strengthen the military Joint Task Force to deal with the militancy.
"We have to be very serious with the situation in the Niger Delta because it threatens the national economy," Buhari said.
"I assure you that everything possible will be done to protect personnel and oil assets in the region," he added.
On Thursday, intruders blocked access to Exxon Mobil's terminal exporting Qua Iboe, Nigeria's largest crude stream. And, earlier this month, Shell workers at Nigeria's Bonga facilities were evacuated following a militant threat.
In February, the Niger Delta Avengers claimed an attack on an undersea pipeline, forcing Shell to shut a 250,000 barrel-a-day Forcados terminal.
The group also claimed responsibility for blasting a Chevron platform in early May, shutting the Warri and Kaduna refineries. Power outages across Nigeria worsened as gas supplies were also affected.
On Friday a locals said a gas pipeline operated by the state energy company had been attacked late on Thursday.
The pipeline, which connects the Escravos oil terminal to Warri, supplies gas to different parts of the country.
Eric Omare, a spokesman for the Ijaw Youth Council, said the attack occurred on Thursday around the village of Ogbe Ijoh, near Warri, "on the pipeline belonging to NNPC (Nigerian National Petroleum Corporation).
Local resident James Dadiowei said he heard a "loud bang" at the pipeline, but an NNPC spokesman was unable to confirm the attack.
(Additional reporting by Tife Owolabi, in Yenagoa, and Anamesere Igboeroteonwu, in Onitsha; writing by Alexis Akwagyiram; Editing by Jonathan Oatis and Alistair Bell)