What we know so far
- Fighting erupted on Sunday morning near army barracks, UN base
- Heavy weapons and gunfire heard, helicopter gunships spotted
- More than 100 soldiers killed in four days of fighting
Intense fighting has resumed in South Sudan's capital, Juba, as an increasingly tense security situation threatened to send the young country back to all-out civil war.
Al Jazeera staff in the city on Sunday heard loud booms, characteristic of heavy weapons, and gunfire coming from the area near the airport, which local sources said had closed. In a post on Twitter, Kenya Airways said that it had suspended flights to Juba "due to [the] uncertain security situation".
Gunfire had earlier been heard in the capital's southwest near an army barracks and a United Nations base.
Violence from Thursday to Saturday killed more than 100 people, mostly soldiers from different armed factions, after gun battles broke out across Juba.
A witness told the Reuters news agency on Sunday that gunfire could be heard in the Gudele and Jebel suburbs, near a military barracks that hosts troops loyal to the country's vice president Riek Machar.
"There were some loud booms, audible from 10km away," Al Jazeera's John Hendren, reporting from Juba, said, referring to the fighting in Jebel.
"It involved tanks, small arms fire and helicopter gunships, so it appeared to be a pretty massive confrontation."
"Three helicopter gunships have just come now and bombed our side," William Gatjiath Deng, a spokesman for Machar's military faction, told the Associated Press news agency.
'Hope of peace is dimming'
The fighting on Friday began outside the presidential compound as President Salva Kiir was meeting with former rebel leader Machar and soon spread throughout the city.
ANALYSIS FROM JOHN HENDREN IN JUBA
I don't think anyone here is talking about advancing peace right now.
The president and the vice president have both said they are committed to doing so, and they of course are the rival factions that came together to form this coalition government - but their armies remain separate, they are clashing and have done so over the past week and sporadically before that.
So this obviously dims hopes for peace in the near future.
The concern is now that if the fighting continues you might have a humanitarian crisis because you will have people trapped in a country where people already are having great difficulty subsisting because of inflation, poverty and other problems here.
So it could be a crisis in the very near future if this fighting does not stop, and that is probably the more immediate concern than the overall peace agreement moving forward - although both the president and the vice president have said they are committed to doing that.
An Al Jazeera correspondent later saw bodies of soldiers on the lawn in the compound, but was forbidden from filming them.
Deng said on Saturday that the fighting had happened near the presidential compound, known as the State House, and in an army barracks.
"In the morning we collected and counted 35 [dead] from the SPLM-IO [Machar's faction] and 80 people from the government forces," he was quoted as saying by Reuters.
Local broadcaster Radio Tamazuj put the number of deaths at 146.
Our correspondent said the latest bout of violence meant "that the hopes of peace were dimming" in the country, which reached the fifth anniversary of its independence on Saturday.
"These are not good times," Hendren said on Sunday.
"Two days ago, the presidential palace was struck - that is a major strike into the heart of government here and shows just how shaky it is.
"And on Saturday, the fifth Independence Day was completely silent because Juba was shut down - it was militarily occupied, which is exactly the opposite of what is supposed to happen here under a peace accord in August."
INTERACTIVE: How far has S Sudan come since independence?
South Sudan was founded with optimistic celebrations in the capital on July 9, 2011, after it gained independence from Sudan in a referendum that passed with a nearly 100 percent of the vote.
The country descended into conflict in December 2013 after Kiir accused Machar, his former deputy who he had sacked earlier that year, of plotting a coup.
Civil war broke out when soldiers from Kiir's Dinka ethnic group disarmed and targeted troops of Machar's Nuer ethnic group. Machar and commanders loyal to him fled to the countryside, and tens of thousands of people died in the conflict that followed. Many civilians also starved.
A peace agreement signed in August collapsed and fighting continues in many parts of the country, despite both leaders joining a unity government two months ago.
Source: Al Jazeera and agencies