(CNN) After days of bloodshed in South Sudan, an uneasy truce is in effect in the world's youngest nation, where soldiers slaughtered dozens last week.

South Sudan President Salva Kiir and Vice President Riek Machar appealed for calm after days of heavy fighting between their soldiers.

Kiir and Machar have separate forces loyal to each side, but more on that later. The two rivals have been embroiled in a power struggle for years, with forces loyal to both engaging in battles and civilians trapped in the crossfires.

Five years after seceding from neighboring Sudan, the fledgling nation got mired in yet another conflict -- this time on the anniversary of its independence.

What initiated the latest clashes? Did they start over a Facebook post? Or was the violence triggered by an attack on a checkpoint? You asked, and we answered.

What is happening in South Sudan?

In 2011, South Sudan split from its northern neighbor, Sudan, in a contentious divorce brokered by international diplomats to end one of the world's longest civil wars.

The split ended decades of violence and bloodshed between South Sudan, which is predominantly Christian, and its Muslim neighbor, Sudan.

Jubilant South Sudan citizens danced in the streets after gaining independence from Sudan. Many believed war was finally behind them and a peaceful existence awaited.

But things have been far from peaceful, and rival factions have turned on one another since the split.

This weekend marked the fifth anniversary of South Sudan's independence. But instead of celebrating another year as a sovereign nation, violence erupted.

Why is South Sudan fighting?

Kiir and Machar are central characters at the heart of the infighting.

The two leaders have been embroiled in a power struggle since late 2013, when the President accused the vice president of trying to oust him through a coup.

The same year, the President fired his entire Cabinet, including the vice president.

Chaos ensued as forces loyal to both battled. Violence quickly spread, with reports of mass killings emerging nationwide.

The three years of violence has left thousands dead, more than 2 million displaced and nearly 5 million others facing severe food shortages.

The conflict has taken ethnic undertones as each side stakes its loyalties --- the Nuer tribe backs Machar while the President hails from the Dinka tribe. Militia sometimes separates terrified residents by ethnicity and massacres those from rival tribes, the United Nations said.

The Dinka and Nuer are the country's biggest ethnic groups, with Dinka the largest at 36% and the Nuer at 16%, according to the CIA World Factbook. The longtime rivals have battled over grazing land and resources for decades.

Why was the vice president reinstated?

As the bloodshed continued, an exasperated international community appealed to Kiir and Machar to do whatever it takes to stop the violence.

As part of a peace deal to end the civil war, the President reinstated his political rival in February. Machar reclaimed his old job as vice president, but troops loyal to each side were not as forgiving, and clashed sporadically.

What role did social media play in the violence?

Depends whom you ask.

South Sudan's ambassador to Kenya told local media that a social media post led to the recent outbreak of violence, which left about 150 people dead.

The vice president's spokesman posted a message on Facebook last week saying Machar was detained at the presidential palace, while he was in fact meeting with the President, the ambassador alleged.

Forces loyal to Machar stepped into action, opening fire outside the palace, Kenyan media quoted the ambassador as saying. When the vice president's forces tried to forcefully enter the palace to check on him, clashes ensued, the ambassador alleged.

CNN has reached out to the ambassador but has not heard back.

The vice president's spokesman, James Gatdet Dak, slammed the ambassador's accusations. He acknowledged posting on Facebook that Kiir "attempted to arrest" the vice president but denied that post sparked the violence.

"Look at this liar who calls himself an ambassador in Kenya," he posted on Facebook. "These people such as this ambassador in Kenya will never learn to tell the truth. They pride in lying."

South Sudan's ambassador to the United Nations, Akuei Bona Malwal, backed his fellow ambassador in saying that the Facebook post was responsible for the violence.

Machar's "huge protection force in 21 mounted vehicles accompanied by an ambulance in which ammunition were concealed, arrived at the main entrance of the presidential palace" as a response to the false post by the vice president's spokesman, he said in a statement.

Other media reports have said the violence started after clashes between the two sides at a checkpoint Thursday killed several soldiers loyal to Kiir.

Malwal said there was an incident in which the vice president's forces attacked a checkpoint in Juba. Two soldiers, two national security personnel and a doctor died.

Is South Sudan safe?

In a country that has not seen much peace in recent years, most nations are not taking chances.

Kenya's largest airline, Kenya Airways, canceled flights to the capital of Juba when the clashes broke out.

The United States has ordered the evacuation of all nonessential embassy employees, and two charter flights departed Juba for Uganda on Thursday. Britain advised against all travel to South Sudan, saying the security situation is deteriorating.

Germany is evacuating its citizens while a plane carrying Italian and European citizens left for Djibouti. India has warned its citizens in the nation to register at its embassy in Juba and stay indoors as the government works to evacuate all nationals.

Uganda's military said it is working to evacuate 2,000 of its citizens gathered in Juba.

The effects of the fighting are spreading internationally. Two Chinese peacekeepers were killed and six others injured last week.

Days after the attacks, the ceasefire appeared to "largely be holding, barring sporadic gunfire," the United Nations said this week.