LAGOS--Nigerian militants attacked an oil ship off the coast of the west African country and took two people hostage, a military spokesman said Sunday.

"The captain, a white man whose identity is still unknown, and the Nigerian engineer of the ship were abducted by the gunmen," Lieutenant-Colonel Musa Sagir told AFP.

"The attack took place 15 nautical miles northwest from the Bonny channel," he said, adding that the military have launched a manhunt for the attackers.

The incident on Saturday came after an attack on Shell oil wells and a flow station in southern Bayelsa state, leading to a cut in the company's output.

Nigeria, Africa's largest oil producer exporting 2.14 million barrels of crude per day, has seen an upsurge in violent attacks on the oil and related industry in the past two years.