JOHANNESBURG, South Africa — South Sudanese militias fired on three U.S. military aircraft on a mission to evacuate American citizens Saturday, wounding four U.S. servicemen, according to military officials.
The planes were headed to Bor, the capital of the eastern state of Jonglei, which is under the control of a rebel military faction associated with sacked Vice President Riek Machar.
Fighting has been intense in the region as South Sudan's army struggles to take back the town, which is north of the nation's capital, Juba.
The planes were fired on as they made their approach, according to a statement from the U.S. military African command. The rescue mission was aborted and the planes turned back and flew to Uganda.
"We can confirm that four U.S. service members were injured today from gunfire directed at their aircraft in South Sudan. The aircraft was participating in a mission to evacuate American citizens in Bor," the statement said.
The aircraft were diverted to Kampala, the Ugandan capital, the Associated Press reported. The servicemen were then flown to Nairobi, Kenya, for treatment.
There were no details on how many Americans were to have been evacuated, who they were or whether another rescue effort would be made.
South Sudan is spiraling dangerously toward civil war, with the army losing its grip on key regions as the military splits and defectors seize control of key areas.
An army division loyal to Gen. James Koang in the main oil-producing region, Unity state, mutinied Friday. Koang later declared himself governor of the state, according to independent local Radio Tamazuj.
Fighting ignited in other parts of the north, the station reported.
The country appears to be splitting along ethnic lines in a confrontation between President Salva Kiir and Machar, whom he dismissed in July, along with the entire Cabinet. Kiir, of the Dinka ethnic group, has accused Machar, a Nuer, of launching a coup attempt.
Machar accused Kiir of stirring ethnic animosity and denied the coup accusation, but in recent days Machar has appeared to be in open rebellion, with reports that rebel generals in Jonglei and Unity states are under his command.
The U.S. Embassy in Juba tweeted Saturday that 450 Americans and other foreigners have been evacuated.
"We will continue to monitor the situation on the ground in order to assess future possibilities for [evacuation] flights from South Sudan," the embassy said.
President Obama, who has just begun a two-week vacation with his family in Hawaii, was told during a call Saturday morning with national security advisor Susan Rice, deputy national security advisors Antony Blinken and Ben Rhodes, and senior director for African Affairs Grant Harris, that the servicemen were in stable condition.
White House officials said the president directed his aides to make it clear that the United States will continue to encourage the resolution of differences in South Sudan through dialogue, and emphasized his belief that the conflict "can only be resolved peacefully through negotiations."
"Any effort to seize power through the use of military force will result in the end of long-standing support from the United States and the international community," White House officials said.
China National Petroleum Corp. is also evacuating hundreds of oil workers.
Last week, 2,000 Nuer youths attacked a United Nations compound in Akobo in Jonglei state, killing two Indian peacekeepers and more than 20 civilians, mainly of Dinka ethnicity, who had taken refuge there.
U.N. peacekeepers are evacuating staff members from several bases in Jonglei state as a result, leaving citizens under the protection of the South Sudanese army, according to local news media.
Times staff writers Dixon reported from Johannesburg and Cloud from Washington. Staff writer Maeve Reston in Hawaii contributed to this report.