South Sudan's President Salva Kiir on Sunday called for an immediate ceasefire to end fighting between the army and former rebel troops loyal to his deputy Riek Machar.
Officials at the president's office put the death toll at 270 people since Friday, comprising 210 casualties on Machar's side and 60 on Kiir's side.
“This is a call to our generals in both armies” for a ceasefire, said Mining Minister Taban Deng, a former rebel negotiator, adding that the president would issue a statement “calling for peace and calm.”
Information Minister Michael Makuei said the South Sudanese needed to “go back” to the peace agreement signed in August 2015, which led to the formation of a transitional unity government in April in an attempt to end more than two years of warfare between Kiir and Machar.
Heavy fighting erupted in the capital on Sunday following several days of clashes, with witnesses reporting gunfire, artillery fire and the presence of tanks and helicopters.
Witnesses said much of the fighting took place in Jebel neighbourhood, where Machar has his residence. Machar's spokesman James Gatdet said Kiir's forces had attacked Machar's positions in Jebel.
"Our forces have captured three tanks ... from President Kiir's forces who attacked Jebel. They are repulsed. Their helicopter gunships have now stopped bombing Jebel after one of them was almost brought down," Gatdet said on Facebook.
Fighting then stopped, but the neighbourhood was still tense, Gatdet added. Rebel spokesman William Gadjiath told dpa that “very heavy fighting” was still going on in several neighbourhoods, with “all our forces ... in the front now.”
One Juba resident, Amanya Joseph, reported fighting near a Catholic seminary. “Artillery, helicopters and light guns are being used. We are just staying indoors,” Joseph said.
The UN mission to South Sudan said both of its compounds in Juba had been damaged by small arms and heavy weapons fire. It did not comment on reports that there had been casualties.
The fighting prompted 1,000 internally displaced people to flee from a UN camp to a UN compound, and hundreds of civilians to seek protection at a UN base, the UN mission said.
Witnesses said thousands of people were also fleeing to Gurei at about 20 kilometres west of the capital. An aid worker who spoke on condition of anonymity estimated that about 10,000 people had left their homes.
The US embassy earlier reported fighting “throughout Juba,” including the airport. Kenya Airways announced it had suspended flights to Juba.
The US State Department late Sunday ordered the departure of non-emergency personnel from the US Embassy in Juba. It also said US citizens were advised to take safety precautions, adding that the embassy’s ability to provide emergency services is "extremely limited."
The United States also strongly condemned the outbreak of fighting and again called on both leaders to immediately restrain their forces to prevent additional violence and bloodshed.
The violence has been going on since Thursday, when clashes erupted between government and rebel troops.
On Friday, fighting broke out near the presidential palace, where Kiir was meeting Machar.
The violence dealt a blow to hopes of peace just as South Sudan was marking the fifth anniversary of its independence from Sudan on Saturday.
A power struggle between Kiir and Machar escalated into a military conflict in December 2013, killing tens of thousands and displacing more than 2 million people.
UN Secretary General Ban Ki-moon said he was “shocked and appalled” by the renewed fighting in Juba and urged Kiir and Machar to “do everything within their power to de-escalate the hostilities immediately.”
European Union foreign policy chief Federica Mogherini and two other EU commissioners said the EU would join other countries "to ensure that peace is restored rapidly, that protection of the UN compounds is given priority, and that the most severe consequences await those who have provoked the latest round of fighting.”
The EU imposed sanctions on military leaders and militia in July 2014. On May 23 this year, EU foreign ministers said that “the EU remains ready to consider further sanctions against any individual who obstructs the peace process in South Sudan.”