Seven Chinese oil workers and two Africans who were kidnapped last week during a rebel attack on a Chinese oil field near the Somali border have been released.

The Ogaden National Liberation Front, a militant group fighting for control of eastern Ethiopia, claimed responsibility for the attack last week, which is run by a division of China’s government-owned energy giant, the China Petroleum and Chemical Corporation. The attack left 65 Ethiopians and nine Chinese workers dead.

The rebels complained that the Ethiopian military was cracking down on ethnic Somalis in Jijiga, a city near the oil field. “Civilians in Ogaden are being told by troops that they will pay the price for the recent ONLF military operation,” the rebel statement said.