Gunmen boarded two fishing vessels just off the coast of Nigeria and took two people hostage, security sources said on Saturday, the latest in a series of hijackings in the waters around Africa's largest oil business.
The captains of the two boats were taken early on Friday, the same day eight pirates took three hostages from an oil supply vessel contracted by Chevron Corp, two security sources close to the incidents said.
Chevron confirmed the attack on the vessel owned by its contractor, the second hijacking on ships hired by the U.S. major off the coast of Nigeria this month.
Both attacks on Friday were in waters around President Goodluck Jonathan's home state of Bayelsa, where military security has been bolstered in recent days amid a fierce political row.
Bayelsa has hundreds of kilometres of oil pipelines and other industry infrastructure crucial to Africa's largest crude exporter. Violence in the Niger Delta's vast swamps and waterways has in the past cut oil output, moving global prices.
The political dispute began earlier this month when the ruling People's Democratic Party listed sitting governor Timipre Sylva as one of four people who failed to get through a screening process to stand in a leadership primary due to be held on Saturday.
They gave no reason for his exclusion. One Western diplomat said Sylva may have become unpopular with someone right at the very top of the party. A lot is at stake.
State governors are among the most powerful politicians in Nigeria, wielding influence over national policy and in some cases controlling budgets larger than small African nations.
Sylva has condemned the deployment of soldiers to a state he is still supposed to run but also publicly urged his supporters to remain calm and keep the peace.
Three ships taken in the same day. It could be a coincidence but elections in the Niger Delta can be volatile and this one particularly so, one security source said.
Nigeria produces more than 2 million barrels per day of crude oil and is a key supplier to the United States, Europe and emerging markets in Asia.
(Reporting by Joe Brock; Editing by Sophie Hares)