A previously unheard-of group calling itself the "Niger Delta Reenforcement Team" sent text messages on Thursday claiming to have blown up a major Shell Petroleum Development Company pipeline in the early hours of the morning.
"We are checking reports claiming an attack on a pipeline at Buguma and can not comment further at this time," a Shell spokesman told AFP.
The message from the group also said it was distinct from the militant Movement for the Emancipation of the Niger Delta (MEND), which announced Saturday it was calling off a three-month-old truce with the government.
A key demand of the militants is that local communities benefit from the region's oil wealth.
Oil is Nigeria's economic mainstay, raking in some 95 percent of export earnings and accounting for about 85 percent of budget requirements for the OPEC member country.