JUBA, South Sudan -- The United States started evacuating non-essential embassy staff and citizens from South Sudan on Wednesday after army factions clashed, killing up to 500 people and raising fears of a broader civil conflict in the two-year-old nation.
Gunbattles erupted on Sunday night between army factions, split along ethnic lines, focused around two army barracks next to the capital in what the government called a coup attempt.
Residents said Juba was calm early on Wednesday after sporadic gunfire overnight.
The government said it arrested 10 people, including seven former ministers, over the "foiled coup" and wanted to question several others, including former Vice President Riek Machar.
The United States, which has urged its citizens to leave South Sudan, said it would start evacuating its people from Juba airport on flights organized by the State Department.
Britain said it was gathering the names of any citizens who wanted to leave and residents said other Western nations were expected to follow. Many aid workers live and work in Juba.
Diplomats said the United Nations had reports of between 400 and 500 people killed and up to 800 wounded in the oil-producing nation, which has been struggled to build a functioning state.
"Most people are scared they might be confronted with a mob or see dead bodies," said one aid worker in Juba, adding that the city was calmer on Wednesday morning, after residents awoke to heavy gunfire and artillery blasts on Monday and Tuesday.
President Salva Kiir blamed the clashes on backers of Machar, who he sacked in July. After his sacking, Machar said he would run for president and accused Kiir of being dictatorial.
Kiir, who before the clashes said his rivals were reviving rifts that led to bloodshed in the 1990s, has faced public criticism for doing little to improve life in one of Africa's poorest nations that won independence from Sudan in 2011.
South Sudan has frequently been caught up in political spats with Sudan, leading to a 15-month shutdown of oil production and exports through a pipeline running through Sudan, cutting off the young nation's almost sole source or revenue.
Though fighting has centred around the capital, there have been some reports of clashes elsewhere.
Hussein Maar, deputy governor of Jonglei State, north of Juba, reported fighting at two barracks a few kilometers from the town of Bor, the place where in 1991 a faction of soldiers loyal to Machar massacred hundreds of Dinka.
Majok Guangdong Thiep, South Sudan's ambassador to Kenya, told Kenyan television the airport would re-open on Wednesday. He said the situation in Juba was under control.
However, an official at Kenya airline Fly540 said a flight due to depart at 8 a.m. local time (12 a.m. ET) from Nairobi for Juba did not leave because the South Sudanese airport was not open.
"Planes due to take off for Juba are empty as people don't want to go there. Even the Sudanese don't want to go home," said the Fly540 official, who asked not to be identified.