The Nigerian army says it has arrested a militant gang leader and 51 of his followers suspected of involvement in a string of oil worker kidnappings in the Niger Delta region.
An army spokesman told reporters Saturday that the suspects were rounded up by a special military task force that polices the delta region.
He said the gang was behind the kidnapping of 19 oil workers freed by security forces earlier this week.
On Friday, the region's main militant group, the Movement for the Emancipation of the Niger Delta (MEND), threatened to carry out more kidnappings in the oil-rich Niger Delta region, despite a military crackdown.
The group said its fighters have been instructed to attack oil facilities and kidnap people.
Royal Dutch Shell said Friday that one of its pipelines in the Niger Delta had been damaged. There was no immediate word about who carried out the attack.
Some information for this report was provided by AFP and Reuters.