Renewed fighting has erupted in South Sudan's capital and forces loyal to Vice President Riek Machar say his residence was attacked by the president's troops, raising fears of a slide back into full-blown conflict in the five-year-old nation.
There was no immediate response on Sunday from the government of President Salva Kiir to the statement by Machar's spokesman.
Earlier, Kiir's information minister, Michael Makuei, said the situation was under control and urged people to stay at home.
The two leaders, who fought each other in a two-year civil war that started in late 2013, had made a joint call for calm after clashes between rival factions broke out late on Thursday.
At least 272 people have been killed in the fighting including 33 civilians, a Health Ministry source told Reuters on Sunday.
Juba residents reported heavy gunfire near the barracks where Machar and his troops have their headquarters. Hundreds of city residents sought shelter in a UN base.
"Dr Machar's residence was attacked twice today including using tanks and helicopter gunships. Helicopters from Kiir's side attacked the residence twice," Machar's spokesman James Gatdet Dak told Reuters.
He added that the situation in Juba had subsequently calmed, echoing comments from residents who said gunfire had eased later on Sunday after several hours of shooting.
The fighting first erupted on Thursday, when troops loyal to Kiir had stopped and demanded to search vehicles of Machar's loyalists.
Gunfire broke out again on Friday between the vice president's bodyguards and the presidential guard, while the two men were holding talks at the presidential State House to defuse tensions.
UN Secretary-General Ban Ki-moon said on Friday the latest violence highlighted a lack of commitment to the peace process and urged the country's leaders to discipline military leaders and work together to implement the peace deal.
Machar and Kiir signed a peace deal in August 2015 to end the conflict, but spent months afterwards wrangling over details. Machar finally returned to Juba to resume his former position of vice president in April.
Analysts say the failure of the two sides swiftly to implement key elements, such re-integrating or demobilising their troops, has cast a shadow over the peace process.
South Sudan's civil war was fought largely along ethnic lines with Kiir, a Dinka, and Machar, a Nuer, drawing support from their respective tribes.