Abuja, Nigeria ? Gunmen in military fatigues seized two foreign oil workers in southern Nigeria early Thursday, the latest violence targeting the petroleum industry in Africa’s largest producer, authorities said.

The workers – a Belgian and a Moroccan – were abducted as they traveled through the southern city of Port Harcourt, where many international energy firms make their bases, Rivers State Police Commissioner Samuel Adetuyi said.

A private security official said the captors wore camouflage uniforms in the style of Nigeria’s military.