Media playback is unsupported on your device Media caption Andrew Harding explains why the Nile is such an important boundary for those fleeing the fighting 
 
 More than 200 civilians in South Sudan have drowned in a Nile ferry accident while fleeing fighting in the town of Malakal, an army spokesman has said. 
 
 He said women and children were among the victims in Sunday's disaster. 
 
 More than 350,000 people have been displaced by the fighting between the South Sudanese government and rebel forces, according to the UN. 
 
 Rebels say they have captured Malakal, which is the gateway to the oilfields of the Upper Nile region. 
 
 However, this was denied by an army spokesman, who said the rebels had been pushed back after heavy fighting in the city. 
 
 "The reports we have are of between 200 to 300 people, including women and children. The boat was overloaded," army spokesman Philip Aguer told the AFP news agency. 
 
 Image copyright AFP Image caption Malakal lies on the east bank of the River Nile 
 
 "They all drowned. They were fleeing the fighting that broke out again in Malakal," he added. 
 
 Malakal is located on the banks of the White Nile - just north of its confluence with the Sobat River. 
 
 Thousands of civilians have been trying to escape the clashes by crossing the river, but many say they simply cannot afford to pay for a boat, says the BBC's Andrew Harding in South Sudan. 
 
 One refugee, Akuch, told our correspondent that she had had to borrow as much as 150 Sudanese pounds (£40; $66) to cross the river. 
 
 Some 9,000 civilians have recently arrived at a UN base in Malakal, almost doubling the number of people seeking shelter there, our correspondent says. 
 
 Image copyright AFP Image caption Some 19,000 people are now seeking shelter at a UN base in Malakal 
 
 Image copyright AFP Image caption Government troops are said to be advancing on the rebel-held town of Bor 
 
 Malakal has already changed hands several times since the conflict began last month. 
 
 In the south, government troops are believed to be advancing on Bor - the only major town previously in rebel hands. 
 
 Meanwhile, talks aimed at securing a ceasefire in South Sudan are currently taking place in the Ethiopian capital Addis Ababa. 
 
 The negotiations are being overseen by the East African regional bloc, Igad. 
 
 The violence erupted on 15 December between forces loyal to President Salva Kiir and soldiers backing Riek Machar, his former vice-president. 
 
 President Kiir is a member of South Sudan's largest ethnic group, the Dinka, while Mr Machar is from the Nuer community - the country's second largest. 
 
 The conflict has seen reports of mass killings along ethnic lines even though both men have prominent supporters among their rival's community. 
 
 The UN estimates that more than 1,000 people have died since the conflict began on 15 December. 
 
 South Sudan seceded from Sudan in 2011 after a long and bloody conflict, to become the world's newest state. ||||| South Sudan's military battled rebels in the streets of the key northern oil town of Malakal Wednesday, the army said, as conflict in the world's newest nation entered its second month. 
 
 The battle for Malakal, the main town in Upper Nile state, is now turning into one of the most bitter in the conflict, with the United Nations reporting tank battles in the streets. 
 
 "There is heavy fighting in Malakal," army spokesman Philip Aguer said, dismissing rebel claims they had taken control of the town. 
 
 Rebel forces staged a fresh attack Tuesday to seize the town, which has already changed hands twice since the conflict began, with rebel spokesman Lul Ruai Kong, boasting the insurgents had "recaptured Malakal". 
 
 "This is not over yet," Aguer said. "The fighting is ongoing." 
 
 South Sudan has been gripped by violence since December 15, when clashes broke out between army units loyal to South Sudanese President Salva Kiir and those supporting ex-vice president Riek Machar. 
 
 According to the United Nations, about 400,000 civilians have fled their homes over the past month, many of them to escape a wave of ethnic violence between members of Kiir's Dinka people -- the country's largest group -- and Machar's Nuer community. 
 
 Up to 10,000 people are believed to have been killed in the fighting, aid sources and analysts say, including over 200 civilians who drowned in a boat fleeing the latest round of fighting in Malakal. 
 
 The East African regional bloc IGAD has been brokering peace talks in neighbouring Ethiopia, although with still little sign of a hoped-for ceasefire agreement. 
 
 Late Tuesday, Minister of Information Michael Makuei spoke optimistically that the two sides may soon "agree on the cessation of hostilities", but the rebel delegation said the key sticking point was still the release of political leaders arrested in Juba. 
 
 Signing a ceasefire and the release of the prisoners are "hooked together", rebel delegate Hussein Mar Nyout told AFP, adding that a truce would only be signed at the same time as a deal on the prisoners. 
 
 The army is also trying to recapture the town of Bor from the rebels, the capital of restive Jonglei state. Aguer, in a statement he has repeated for over a week, said that the army was "still marching on Bor". 
 
 "Frontlines there have so far been quiet this morning, but clashes can break out at any time," he said. ||||| A South Sudan army soldier, with his head covered, looks on in Malakal, 497 km (308 miles) northeast of capital Juba, December 30, 2013 a few days after retaking the town from rebel fighters. 
 
 A South Sudan army soldier stands next to a machine gun mounted on a truck in Malakal town, 497km (298 miles) northeast of capital Juba, December 30, 2013 a few days after retaking the town from rebel fighters. 
 
 JUBA Uganda's president said on Monday the nations of East Africa had agreed to move in to defeat South Sudanese rebel leader Riek Machar if he rejected a ceasefire offer, threatening to turn an outburst of ethnic fighting into a regional conflict. 
 
 Hours after President Yoweri Museveni's ultimatum, rebels and the feared "White Army" militia clashed against government troops just outside Bor, the capital of Jonglei state, officials said. 
 
 They said the government side was braced for a "full scale" attack on the town, seized by rebels for several days earlier this month and the site of an ethnic massacre in 1991. Thousands of civilians had fled for the surrounding swamps. 
 
 Two weeks of clashes have already killed at least 1,000 people in the world's newest nation, unnerved oil markets and raised fears of a civil war in a region ravaged by fighting in Central African Republic and Democratic Republic of Congo. 
 
 "We gave Riek Machar four days to respond (to the ceasefire offer) and if he doesn't we shall have to go for him, all of us," Museveni told reporters in South Sudan's capital, Juba, referring to a December 31 deadline. 
 
 Asked what that meant, Museveni said: "to defeat him". 
 
 He did not spell out whether South Sudan's neighbors had actually agreed to send troops to join the conflict that erupted in Juba on December 15. 
 
 But his words underlined the scale of regional concern over the fighting that has spread to South Sudan's oil-producing states - often along ethnic lines, between Machar's group, the Nuer, and President Salva Kiir's Dinka. 
 
 Past conflicts in South Sudan have sent refugees pouring over its borders and spurred on rebels in neighboring countries, including the Lord's Resistance Army in Uganda. 
 
 There was no immediate confirmation of the pact to take on Machar from other East African countries, which have been trying to mediate and last week gave the sides until December 31 to lay down their weapons. 
 
 Kenya's presidential spokesman, Manoah Esipisu, said it would be inappropriate to comment until the deadline has passed. Machar himself did not respond to calls. 
 
 Information Minister Michael Makuei said the rebels want to take Bor ahead of the deadline so Machar "can talk from a position of strength" once peace talks start. 
 
 "This is why he has been intransigent," Makuei said. 
 
 FIGHTING DISPLACES 180,000 
 
 The United Nations, Washington, and other Western countries that have poured hundreds of millions of dollars of aid into South Sudan since it won its independence from Sudan in 2011 have also scrambled to stem the unrest. 
 
 U.S. Secretary of State John Kerry has had regular contact with regional leaders and spoken almost daily to both Kiir and Machar since December 20 to push for a ceasefire, State Department spokeswoman Marie Harf said. 
 
 "What we have said is there is no place for violence here and the sides need to take a step back and move towards a mediated negotiated political dialogue," Harf said. 
 
 Meanwhile, U.S. special envoy to South Sudan, Donald Booth, was in Juba on Monday "attempting to work with both President Kiir and former Vice-President Machar to finalize details of a political dialogue and arrange for negotiations to begin in coming days," Harf added. 
 
 "It is a very complicated and tenuous situation," she said, adding that 400 U.S. official and private citizens had been evacuated from South Sudan since the trouble erupted. " 
 
 Fighting has displaced at least 180,000 people, including 75,000 seeking refuge inside U.N. bases across the country, according to U.N. figures. 
 
 Falling global oil prices have been kept in check by fears there could be further cuts to output in South Sudan, which BP says holds the third-largest oil reserves in sub-Saharan Africa after Angola and Nigeria. 
 
 South Sudan's oil production has fallen by nearly a fifth to 200,000 barrels per day after oilfields in Unity state were shut last week due to the fighting. 
 
 Control Risks analyst Paul Gabriel said Museveni's words were probably aimed at pressing Machar to join talks, rather than a threat of imminent intervention. 
 
 There was currently little regional appetite to get involved in the fighting, though "that might change quickly if there is a situation where Juba or President Kiir is threatened," Gabriel added. 
 
 Kiir sacked his longtime political rival Machar in July and then accused him of starting the December fighting to try to seize power. 
 
 Machar denied that charge, but has since retreated into the bush and acknowledged he is leading rebel fighters. He has responded coolly to the ceasefire offer and the army, the SPLA (Sudan People's Liberation Army) has said it has continued to fight his soldiers. 
 
 "WHITE ARMY" THREAT 
 
 "The SPLA forces in Bor town are on maximum alert," SPLA spokesman Philip Aguer said on Monday night after skirmishes with the Nuer "White Army" militia just outside the town. 
 
 The White Army - made up of Nuer youths who dust their bodies in white ash - has in the past sided with Machar. 
 
 But a spokesman for the government of South Sudan's Unity state, now controlled by forces loyal to Machar, on Sunday denied Machar was in control of the White Army fighters, raising the prospect that the violence was spreading beyond the control of widely recognized ethnic leaders. 
 
 Thousands of civilians have fled from Bor over the past few days, crossing the White Nile river and heading for the swamps, Makuei told Reuters. Nuer militias massacred Dinkas in Bor during an outburst of ethnic fighting in 1991. 
 
 "They (the White Army) have attacked the village of Mathiang (18 miles from Bor), killing civilians and burning civilian houses down. They are butchering civilians," said Bor's mayor, Nhial Majak Nhial, from the town, 190 km (120 miles) north of Juba. 
 
 Nhial said he was urging civilians to escape Bor as the White Army militia neared. 
 
 The reports of clashes and advances came from remote areas largely inaccessible to journalists and it was not possible to verify them independently. 
 
 Tribal elders over the weekend persuaded many of the Nuer youths advancing on Bor to abandon their march, but officials said about 5,000 refused to turn back. 
 
 (Additional reporting by Lesley Wroughton in Washington, reporting, writing by Drazen Jorgic; Editing by Richard Lough, Andrew Heavens, Philippa Fletcher and Dan Grebler)
– Some 400,000 people have now fled South Sudan amid weeks of fighting, the UN says; at least 200 drowned on a ferry trying to escape. "The reports we have are of between 200 to 300 people, including women and children. The boat was overloaded," an army rep tells AFP. He says the incident occurred today, while other reports indicate it was overnight Sunday. "They all drowned." He said they were fleeing Upper Nile state capital Malakal, which has been under both rebel and government control; it’s situated near the state’s oil fields. The rebels have launched a new attack on the area, where some 19,000 people have sought shelter at a peacekeeping base, a UN spokesman says. Malakal, the BBC notes, sits near the White Nile, which thousands of civilians have tried to cross in a bid to escape. Many, however, can’t afford a boat ride; one refugee tells the BBC she had to borrow $66 to get across. A recent estimate puts the death toll of the conflict at 10,000.