Fresh clashes have broken out in the South Sudanese capital Juba, and at least 66 soldiers have been killed, a day after President Salva Kiir said security forces had put down an attempted coup by supporters of his former deputy.
The US embassy said on its Twitter account late on Tuesday that that all of its citizens in the country should "depart immediately". The account tweeted that it would outline evacuation options on Wednesday morning.
"So far we have lost seven soldiers who died while they were waiting for medical attention and a further 59 who were killed outside," doctor Ajak Bullen said on the local Radio Miraya.
Poor communications in Juba, where the mobile phone system has not operated since Monday evening, meant it was difficult to obtain a broad picture of the number of dead during the clashes, which have involved heavy arms and artillery.
Kiir said on Monday the fighting between army factions was a bid to seize power by the former vice president, Riek Machar, whom he sacked in July.
The two men, from different ethnic groups, which have clashed in the past, have long been political rivals. Analysts said divisions between them run deep and rivalries in army ranks have long simmmered.
Al Jazeera's Rawya Rageh, reporting from neighbouring Nairobi, spoke to South Sudan's Information Minister Michael Makuei Lueth who confirmed at least 10 very senior former government officials have been arrested, including six cabinet ministers. The government named the men on its website.
There are conflicting reports about the whereabouts of Riek Machar. The government claims he is on his way to Unity State, whereas Machar's spokesperson said he is in fine condition and "very much still in Juba", Rageh said.
Gunfire - including the sporadic firing of heavy weapons - resumed in the early hours of Tuesday and was still audible at 9am (0600 GMT). It appeared to come from a military headquarters, a few kilometres from the centre of town.
|South Sudan's president says coup attempt 'foiled'
Residents near Juba airport, which has been closed since Monday, were woken before dawn by gunshots and blasts, a UN worker said. Others also reported bouts of shooting.
The streets of Juba were deserted, with only military vehicles to be seen and civilians barricaded in their homes.
Kiir had said in a statement on Monday that security forces had regained control, although a dawn-to-dusk curfew had been imposed.
"The attackers went and [the] armed forces are pursuing them," Kiir said. "I promise you today that justice will prevail."
Details of the claimed coup remained sketchy, but South Sudan's Foreign Minister Barnaba Marial Benjamin told the Associated Press news agency that troops in the main army base raided a weapons store in Juba but were repulsed.
Civilians take refuge
The UN deputy special representative for South Sudan, Toby Lanzer, told Al Jazeera on Tuesday that about 16,000 civilians were now taking refuge from the fighting in two UN compounds.
"We will of course do everything we can do protect people. Many people who are coming require health care of all types," he said.
"Some people have been injured. We've got challenges of a variety - and the water and sanitation situation is also something that we are grappling with."
Tension had been mounting in South Sudan since Kiir's sacking of Machar. The men belong to different ethnic groups - Kiir to the Dinka, the most powerful, and Machar to the Nuer, but it is not clear whether this latest tension is due to ethnic or political divisions.
Machar, who has expressed a willingness to contest the presidency in 2015, told Al Jazeera in July that if the country is to be united it cannot tolerate "one man's rule or it cannot tolerate dictatorship."
His sacking, part of a wider dismissal of the entire cabinet by Kiir, had followed reports of a power struggle within the ruling party.
South Sudan's government has struggled to create a functioning state since it declared independence from Sudan in 2011 after years conflict with Khartoum during a war that often saw south-south clashes.