OTTAWA -- The federal government is advising Canadians in South Sudan to leave immediately amid violence that has killed hundreds of people.
Foreign Affairs issued an advisory Saturday evening saying Canadians in the African country should leave and is advising Canadians not to travel there.
"You are urged to leave now by commercial means, as it may become increasingly difficult to do so if the situation deteriorates further," an advisory on the Foreign Affairs website says.
"The Juba (South Sudan capital) airport is open, and tickets for commercial flights are available."
Federal government sources say about 100 Canadians are registered with the government as being in the African country.
South Sudan officials blame ethnic tensions for the violence that started last weekend and world leaders are concerned it could ignite a full-blown civil war.
The south fought a decades-long war with Sudan before a 2005 peace deal resulted in a 2011 referendum that saw South Sudan break away from the north, taking most of the region's oil wealth with it.
U.S. President Barack Obama warned Saturday that using military force to gain power in South Sudan could cost the country international support.
Obama was reacting to reports that four U.S. service members were wounded when South Sudanese militias fired on three U.S. military aircraft on a mission to evacuate American citizens. He encouraged talks to help end the violence in South Sudan.
"Any effort to seize power through the use of military force will result in the end of longstanding support from the United States and the international community," the president said, according to White House officials.
South Sudan is spiralling dangerously toward civil war, with the army losing its grip on key regions, as the military splits and defectors seize control of key areas.
White House officials said Obama directed his aides to make it clear the United States will continue to encourage the resolution of differences in South Sudan through dialogue and emphasized his belief the conflict "can only be resolved peacefully through negotiations."
Obama, who has just begun a two-week vacation with his family in Hawaii, was updated on South Sudan during a call Saturday morning with national security adviser Susan Rice, deputy national security advisers Tony Blinken and Ben Rhodes, and Grant Harris, senior director for African affairs.
The U.S. planes had been headed to Bor, north of Juba, the capital. Juba is the main town in the eastern state of Jonglei, which is under the control of a rebel military faction associated with sacked vice-president Riek Machar. Fighting has been intense in the region as South Sudan's army struggles to take back the town.
The UN Security Council on Friday said the weeklong violence could affect neighbouring countries and the entire region.
Rick Roth, a spokesman for Foreign Affairs Minister John Baird, says Canada is deeply concerned about the violence.
"Canada calls for an immediate stop to the fighting in South Sudan and expresses its strong support for the efforts of the UN mission and the African Union to help the parties resolve the current conflict through dialogue," Roth said in an email.
The U.S. Embassy in Juba tweeted Saturday that 450 Americans and other foreigners have been evacuated in recent days.
"We will continue to monitor the situation on the ground in order to assess future possibilities for (evacuation) flights from South Sudan," the embassy said.
-- The Canadian Press, Los Angeles Times