LAGOS, Nigeria (AP) -- Rebels in Nigeria's troubled and oil-rich Niger Delta said Friday they have been contacted by the kidnappers of two U.S. mariners and can help ensure their safety.
Nigerian Navy spokesman Capt. Kabir Aliyu said a rescue operation has been mounted for the men, whom U.S. officials identified as the captain and chief engineer of the U.S.-flagged C-Retriever offshore supply vessel taken in a Wednesday afternoon attack off the coast of Nigeria.
An email reportedly from the Movement for the Emancipation of the Niger Delta said Friday the Americans were captured by a "heavily armed auxiliary outfit" off the town of Brass in the Gulf of Guinea.
"The Americans will not be handed over for our direct custody but we will have the influence to visit them and ensure that they are well looked after until their subsequent release," the statement said.
Almost all foreigners kidnapped are released once ransoms are paid. A U.S. civilian kidnapped last year from Nigeria's oil-refining city of Warri was freed after a week in captivity.
Nigeria's navy has rescued at least two hostages this year and reported killing several pirates in counterattacks to prevent ship hijackings.
The MEND statement warned such attacks are the result of "unresolved root issues" compounded by the detention of several rebels and "a monumental Niger Delta amnesty fraud," referring to a 2009 peace agreement in which several MEND leaders were bought off by the government. Some now command security companies protecting the assets of the international oil companies that were the enemy.
The agreement has brought relative peace to the area on land though activists and criminals are blamed for the theft of an estimated 200,000 barrels of oil a day.
Offshore, however, the International Maritime Bureau warned that piracy is on the increase with heavily armed Nigerian gangs launching more attacks and expanding their area of operations to other countries in the Gulf of Guinea.
In a report published Oct. 17, the bureau said attacks in the gulf were up by one-third with more than 40 piracy attacks this year and six oil tankers and an offshore supply ship hijacked. It said 32 crew members were taken hostage off the coast of Nigeria and two off Togo's coast this year.
But many attacks are not reported and an intelligence brief from The Soufan Group on Friday said the actual number may be double the number reported.
The security intelligence group noted that about 30 percent of U.S. oil and 40 percent of European oil supplies pass through the dangerous waters and that the number of attacks has increased despite a new cooperation between the navies of Nigeria and neighboring Benin.
The Gulf of Guinea has overtaken Somalia has the world's hotspot for pirates as international navies patrol waters off Somalia and ships that only pass through there are heavily armed. Ships coming into the territorial waters and ports of Gulf of Guinea nations are not allowed to carry arms.
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