Gunmen hijacked a vessel belonging to French oil services group Bourbon off Nigeria's Niger Delta today as it travelled towards a Royal Dutch Shell offshore oilfield, Reuters quoted security sources as saying. The vessel was carrying four expatriates from Cameroon, Ghana and Lebanon when it was attacked near the Bonny Fairway buoy, a major shipping route for the Nigerian oil services industry, one of the sources said. "It was hijacked by gunmen in about five speedboats. The vessel lost contact with the control room around the Okwori oilfield area near Bonny," the source, a private security contractor working in the oil industry, told Reuters. A second security contractor confirmed the vessel had been travelling to Shell's Bonga offshore field when it was seized.