The militant Movement for the Emancipation of the Niger Delta Saturday claimed responsibility for Friday's abduction of six oil workers from a vessel belonging to Italian oil company Eni, from Nigeria's volatile Niger Delta, DPA reported. It gave no reason for the abduction, which sent price of a barrel of crude oil soaring to 92 dollars at the weekend. The kidnap of the oil workers also forced Eni to shut production of some 50,000 barrels of crude oil in its facility in the area. The MEND gunmen raided the vessel, Mystras, some 85 kilometres off the coast at dawn Friday, seizing the workers who were of Polish, Filipino and Nigerian origin. It was the second abduction in one week. Gunmen attacked an offshore facility belonging to Anglo-Dutch oil giant Shell last Saturday from where they abducted seven oil workers including four Nigerians, a Briton, a Croatian and a Russian, who were released days later. The oil-rich Niger Delta has been plagued by militant attacks on foreign oil companies, with some 200 workers abducted since the start of 2006, many of them released after a short while and once a ransom has been paid. President Umaru Yar'Adua, elected in April, has pledged to pacify the south, but his calls for peace have not been heeded by the militants, who demand a greater say in their region's oil wealth.