South Sudan's crisis is only three weeks old but it has already displaced 189,000 people, according to the United Nations refugees agency. The crisis began on Dec. 15 as fighting between ethnic Dinka and Nuer in the presidential guard (the president, who is Dinka, had earlier fired the vice president, who is Nuer). That fighting has quickly spread, with open rebellion in parts of the country and rising fears of all-out ethnic conflict between the country's two largest groups.

The United Nations has just released this map showing South Sudan's already-huge populations of people who have been displaced by the crisis, either into internal camps or out of the country entirely.

A few things you'll notice right away, all of them bad. First, people are getting displaced across huge swathes of the country, suggesting that fighting and instability are spreading wide and fast across the Texas-sized country.

Second, most of the displaced people are in South Sudanese camps, meaning that the government is responsible for them, which is scary since South Sudan's government was not really capable of caring for those people when they weren't displaced.

Third, an awful lot of displaced civilians are staying outside of U.N. bases (those people are denoted by orange boxes), which makes it really hard for the United Nations to provide them with services, such as food and shelter.

And, fourth, at least a few thousand people have fled into Sudan, the country that the South Sudanese spent decades fighting to break away from, which is not in itself hugely significant except as a depressing symbol of South Sudan's troubled start as an independent country.

South Sudan's crisis is not yet an all-out ethnic conflict. But there are some awfully worrying signs. That so many people have fled their homes is one indication that people are worried about being targeted for their ethnicity. As NPR's Gregory Warner reported from the country a few days ago, "People are starting to ask who their neighbors are."

One of the thousand or so people killed so far is Andrew Bith Abui, one of the "Lost boys of Sudan" who had won asylum in the United States but later returned to South Sudan to help build the newly independent country. Abui was killed in what appears to have been ethnic violence in his home town.

“They attacked the village and overran the police,” a relative told The New York Times. “They killed anybody just because they belonged to another tribe.”