Fierce battles raged on Tuesday in South Sudan's capital Juba, witnesses said, as troops loyal to the president fought rival soldiers accused of staging a coup in the world's youngest nation.
The continued gunfire, including the sporadic firing of heavy weapons, resumed in the early hours of Tuesday as terrified residents barricaded themselves in their homes or attempted to flee the city.
South Sudan's Under-Secretary for Health Makur Korion said on local radio that at least 26 people had so far been killed in the violence. At least 130 more are reported to have been wounded.
"We can still hear sporadic shooting from various locations. The situation is very tense," Emma Jane Drew of the British aid agency Oxfam told AFP by telephone from Juba.
"It's continued shooting. Shooting could be heard all through the night. We don't know who is fighting who."
Drew said her team was unable to leave their compound because of the fighting, which began late on Sunday.
South Sudan's President Salva Kiir has accused troops loyal to his arch-rival, former vice president Riek Machar who was sacked from the government in July, of attempting a coup.
On Monday, Kiir said his troops were "in full control of the security situation in Juba", and imposed an overnight curfew on the city -- only for the fighting to resume again.
The independent radio station Tamazuj said clashes were taking place around compounds belonging to Machar or his loyalists.
UN radio said at least 7,000 civilians had taken refuge at UN offices. An AFP reporter said residents living in areas close to military bases were using any lull in the fighting to flee for safer areas, although many said they were too afraid to move.
"We are afraid of going outside," said Juba resident Jane Kiden.
"We had wanted to go out and buy food from the market, but how can you go with the shooting? I am staying at home with my children."
There were also unconfirmed reports of troops conducting violent house-to-house searches.
"We have heard unconfirmed reports of house-to-house military checks of civilians including the use of brutality and violence, though this is unconfirmed," Oxfam's Drew said, raising concerns of an ethnic dimension to the fighting.
"It is a very strong possibility. We have certainly received reports of that, but we're locked in the compound, relying on word of mouth," she said.
Oil-rich but impoverished South Sudan won its independence in 2011 after its people voted overwhelmingly in a referendum to split from the north and form a new nation.
But the country has struggled with ethnic violence and corruption, and political tensions have worsened in recent weeks between rival factions within the ruling party, the Sudan People's Liberation Movement (SPLM).
Machar leads a dissident group within the SPLM and had been seen as the main challenger to Kiir. The rivals hail from different ethnic groups and had in the past fought on different sides during Sudan's civil war.
Officials have said several former government ministers have been arrested, although the whereabouts of Machar is unclear.
Communications in Juba continued to be sporadic, with most phone lines down and the main airport closed, diplomats and civil aviation officials said.