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By Tife Owolabi

YENAGOA, Nigeria, May 22 (Reuters) - A crude oil pipeline in Nigeria's southern state of Bayelsa operated by the local subsidiary of Italy's Eni was attacked on Sunday, the Nigeria Security and Civil Defence Corps (NSDC) said.

The attack comes just days after President Muhammadu Buhari said he had heightened the military presence in the oil-rich Niger Delta region, where attacks in the last few weeks have driven the country's oil output to a more than 20-year low.

Desmond Agu, a spokesman for the NSDC, a government agency, said the Agip pipeline was attacked in the early hours of Sunday, around 12:30 a.m. (2330 GMT Saturday).

"A gang of armed youths ... vandalised pipeline along Azuzuama axis of the Tebidaba-Brass pipeline with dynamite and ignited fire on the line," he said, adding that one of the suspected attackers had been arrested.

Eni, which operates in Nigeria through its subsidiary Nigerian Agip Oil Company, could not be immediately reached to comment on the attack.

Former militants have called for a halt to a resurgence of attacks in the Niger Delta, saying it is an unnecessary distraction for Buhari's administration.

(Writing by Alexis Akwagyiram. Editing by Jane Merriman)