Fierce battles have raged in the South Sudan capital, Juba, as troops loyal to the president fought off an alleged coup in the world's youngest nation.
Witnesses say the gunfire, including the sporadic firing of heavy weapons, resumed in the early hours of Tuesday and went into the morning as terrified residents barricaded themselves in their homes or were attempting to flee the city.
South Sudan 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."
The fighting began late on Sunday and South Sudan President Salva Kiir has accused troops loyal to his arch rival, former vice president Riek Machar, who was sacked from the government in July, for attempting a coup.
President Kiir also said on Monday that his troops were "in full control of the security situation in Juba" and imposed an overnight curfew on the city.
Thousands of civilians have reportedly taken refuge at UN offices, and an AFP reporter said many 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 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."
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 Peoples' 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.
