including nine Chinese workers.

Witnesses said dozens of rebel gunmen crept up to the oil field at dawn and unleashed an intense barrage of machine gunfire at Ethiopian soldiers posted outside. After a fierce hourlong battle, the rebels rushed away, taking with them seven Chinese hostages.

Ethiopia, a close American ally, has been wracked by a number of separatist groups for years. Thousands of Ethiopian troops are bogged down in Somalia where they face increasingly intense resistance. Ethiopia’s intervention in Somalia may have spurred the rebels to attack the oil field.

China has become increasingly involved in Africa as it hunts for oil and other resources to feed its booming economy. Chinese workers often operate in areas considered unstable and several have already been kidnapped in the volatile Niger Delta in Nigeria.