NAIROBI, Kenya (AP) — Gunfire hit three U.S. military aircraft trying to evacuate American citizens in a remote region of South Sudan that on Saturday became a battle ground between the country’s military and renegade troops, officials said. Four U.S. service members were wounded in the attack in the same region where gunfire downed a U.N. helicopter the day before. The U.S. military aircraft were about to land in Bor, the capital of the state of Jonglei and scene of some of the nation’s worst violence over the last week, when they were hit. The military said the four wounded troops were in stable condition. The U.S. military said three CV-22 Ospreys — the kind of aircraft that can fly like a helicopter and plane — were “participating in a mission to evacuate American citizens in Bor.” A South Sudan official said violence against civilians there has resulted in bodies “sprinkled all over town.” “After receiving fire from the ground while approaching the site, the aircraft diverted to an airfield outside the country and aborted the mission,” the statement said. “The injured troops are being treated for their wounds.” It was not known how many U.S. civilians are in Bor. After the aircraft took incoming fire, they turned around and flew to Entebbe, Uganda. From there the service members were flown to Nairobi, Kenya aboard a U.S. Air Force C-17 for medical treatment, the statement said. An official in the region who insisted on anonymity to share information not made public said the Americans did not tell the top commander in Bor — Gen. Peter Gadet, who defected from the South Sudan military this week — that they were coming in, which may have led to the attack. The U.S. statements said the gunfire was from unknown forces.