Officials in Nigeria say at least four foreign oil workers have been taken hostage in the latest in a series of kidnapping in the country's oil-rich south.
Officials say the workers were taken from the town of Eket Tuesday in the Niger Delta region. No other details were immediately available.
On Monday, militants took 25 Nigerian oil workers hostages from their convoy of boats supplying oil fields in the Delta. Royal Dutch Shell, which employees the contractors, say nine of them were later released. The company says it has no further details about the 16 still in captivity.
A group of local separatists, called the Joint Revolutionary Council claimed responsibility for that kidnapping, and said the abductions were aimed at obtaining the release of a separatist leader - Niger Delta People's Volunteer Force leader Mujahid Dokubo Asari.
Militant attacks on Nigeria's oil industry - Africa's largest - have cut production by nearly a third this year.
Despite the region's vast oil wealth, local people remain impoverished. Militants have demanded a greater share of oil revenue, however many recent kidnappings are believed to have been carried out strictly for ransom money.
Some information for this report was provided by AP and Reuters.