( CNN ) -- Order has been restored in South Sudan after fighting that left about 500 people dead , the Ministry of Foreign Affairs said Wednesday . Government forces are now in charge of the situation , and flights have resumed at Juba International Airport , the ministry said . The United Nations , however , is warning that the crisis is not over . Joseph Contreras , U.N. acting spokesman on South Sudan , said , `` It is a very , very fluid situation , so I do n't think the country is out of the woods yet . '' U.N. Secretary-General Ban Ki-moon also spoke Tuesday of being `` deeply concerned '' about South Sudan . `` There is a risk of this violence spreading to other states , and we have already seen some signs of this , '' Ban said . Meanwhile , the South Sudanese government said its forces are in `` absolute control of the situation '' and that Sunday 's coup attempt was not based on ethnic divisions but rather on `` the power ambitions '' of the coup plotters . About 800 more people have been wounded in the violence , Information Minister Michael Makuei Lueth said earlier . He said bodies are still being found in forests and many of those who were wounded are dying in hospitals . Deadly clashes in Africa 's newest nation began Sunday evening . President Salva Kiir later said his forces had halted a coup attempt . U.N. officials have expressed deep concern about the unrest , saying between 15,000 and 20,000 people have taken shelter in the organization 's compounds in the capital , Juba . `` There are many , many people who have run away , and there are also people who have been killed , '' one woman who fled the fighting said . `` Now there is a woman who has a baby who was shot in the back and died . '' In Bor , a town 87 miles north of Juba , the South Sudan Red Cross reported 19 civilians were killed , said U.N. spokesman Martin Nesirky . Meanwhile , about 800 people gathered at a U.N. camp in Bor to seek protection , he added . Gunfire was still ringing out in Juba as recently as Tuesday . But Makuei said Wednesday the situation in the city had returned to normal , with people returning to work , flights resuming and government offices opening . He said the rebels who have clashed with government forces had moved closer to the Nile River . Fears of ethnic tensions . U.N. officials have said they are worried the recent fighting is based on ethnic divisions . Makuei disputed that suggestion , saying people from different states and tribes rose up against the government , which is now fighting back . In a televised address Monday , Kiir blamed soldiers loyal to his sacked deputy , Riek Machar , for starting the fighting Sunday evening . Ten people were arrested in connection with the foiled coup and five others are still at large , according to a statement posted Tuesday on the South Sudan government website . Those five include Machar , the government said on its Twitter account . U.N. leader Ban spoke with Kiir by phone Tuesday , expressing his concern about the fighting . `` I spoke to President Salva Kiir yesterday morning , urging him to do everything possible he can to end the violence and to ensure respect for human rights and the rule of law , '' Ban told reporters in New York on Wednesday . `` I also impressed on him the need to resume dialogue with the political opposition . I welcome the reports this morning that President Salva Kiir is willing to enter into such talks . '' He urged `` all parties to cease hostilities immediately '' and called on the government to `` exercise restraint in the management of the situation and to guarantee the protection of all civilians regardless of their ethnicities , '' the United Nations said . Medical crisis . The International Committee of the Red Cross has said it is providing Juba 's two major hospitals with support , such as wound-dressing materials , to cope with the heavy influx of patients . More than 300 people have been admitted to Juba Teaching Hospital and Juba Military Hospital over the past two days , the organization said Tuesday . `` We know there are more people who need care , but they are having difficulty reaching health care facilities because of the security situation and the lack of available transportation , '' Felicity Gapes , a Red Cross delegate leading the medical response on the ground , said in a prepared statement . The State Department said U.S. citizens in South Sudan should leave immediately and ordered the departure of nonemergency U.S. government personnel from the country . In a tweet , the U.S. Mission in Juba said an evacuation flight for Wednesday was full . With a dusk-to-dawn curfew in effect , it said the airport would close at 5.30 p.m. locally . Britain 's Foreign Office announced the temporary withdrawal of some embassy staff and dependents . Kiir 's dismissal of his Cabinet in July further inflamed deep tensions between his Dinka community and Machar 's Nuer community . South Sudan formally split from Sudan in 2011 after a referendum , following decades of conflict . Numerous armed groups remain active in the oil-rich country . Britain 's minister for Africa , Mark Simmonds , urged leaders on all sides to end hostilities and for civilians to be protected . `` After years of conflict , the people of South Sudan expect their leaders to resolve their differences through political , instead of military , means , '' he said in a prepared statement . `` Unless there is restraint from all sides it will be impossible to move the country further towards true national reconciliation . '' Editors ' Note : This article has been edited to remove plagiarized content after CNN discovered multiple instances of plagiarism by Marie-Louise Gumuchian , a former CNN news editor . CNN 's Aliza Kassim , Nana Karikari-apau , Khushbu Shah and Michael Martinez contributed to this report .
NEW : U.N. leader says South Sudan violence shows `` some signs '' of spreading . NEW : South Sudan Red Cross reports 19 killed in Bor , U.N. says . NEW : UN chief Ban Ki-moon calls for an immediate cease-fire and a return to peace talks with the government. NEW : South Sudan government must resume dialogue with opposition , Ban adds .