Nigeria's most prominent militant group says it has attacked another oil facility in the restive Niger Delta region.
The Movement for the Emancipation of the Niger Delta, or MEND, says it blew up a major crude oil pipeline near Rumuekpe in Rivers state Wednesday.
There was no immediate confirmation of the claim. MEND has claimed to carry out three other attacks since Tuesday - including an assault on a Shell oil flow station at Orubiri, also in Rivers state.
MEND says it teamed up with a new ally, the Niger Delta Volunteer Force, to destroy that facility.
The militants warned today that they may broaden their so-called "oil war" beyond Rivers state and attack offshore oil platforms.
General Mohammed Yusuf, a spokesman for the Nigerian army, called the threats propaganda, and said the military is taking counter-measures to keep the militants in check.
On Tuesday, Nigeria's military said MEND released two South African oil workers who were kidnapped last week. In an e-mail today, the militant group said they are still holding the workers and called that report a "blatant lie."
The militants declared an all-out war against the government last Saturday, in response to what it called unprovoked attacks on its positions.
The militants are demanding that impoverished Delta residents get more of the region's oil wealth. The group launched its campaign against the government and oil companies in late 2005.
The attacks and kidnappings, some carried out by local gangs, have slashed Nigeria's daily crude oil output by more than 20 percent.
Some information for this report was provided by AFP, AP and Reuters.