Rebels in oil-rich Nigeria say they have set off an explosion at a pipeline in the southern part of the country.
The Joint Revolutionary Council, a little-known rebel group in the Niger Delta, said its members "attacked and exploded" part of a pipeline in Buguma, Nigeria.
Shell said it is aware of the claim but could not immediately confirm that an explosion had taken place.
However, a spokesman for the Nigerian military, Timothy Antigha, said, "There was an act of sabotage on a Shell pipeline." He said it caused no injuries or deaths.
The Joint Revolutionary Council and a better-known rebel group, the Movement for the Emancipation of the Niger Delta, or MEND, both have attacked oil pipelines in the Niger Delta. They say the poverty-ridden region produces oil but does not sufficiently benefit from the wealth that the oil generates.