While Ukraine prepares for a new era without President Viktor Yanukovych, tensions are brewing in the nation's ethnically intermixed South and East. Yanukovych supporters have staged counter-rallies around the country, and rival protesters came to blows on Thursday in Crimea, an autonomous republic of Ukraine.
After armed men took over the parliament and government buildings in the Crimean capital and raised the Russian flag, thousands gathered in opposing rallies that descended into clashes, Bloomberg reports.
Here are four reasons why tensions are running so high in Crimea amid Ukraine's upheaval.
Crimea is an autonomous republic of Ukraine with close ties to Russia.
Crimea is a peninsula that juts out of southern Ukraine into the Black Sea and toward Russia, in some places separated from its neighbor by only a few kilometers across the water.
During its turbulent history, the BBC explains, Crimea has been ruled by Scythians, Greeks, Goths, Huns, Bulgars, Kazhars, Kipchaks, Turks, Mongols and the Roman, Byzantine and Russian empires.
Soviet leader Nikita Khrushchev transferred the Crimea to Ukraine in 1954 and when the Soviet Union collapsed, Crimea became part of the newly-independent Ukrainian Republic. Crimea was given autonomous status, with an independent government and parliament.
Russia has maintained strong connections to Crimea. It has long been the seaside playground of Russia's elite and retains a strong place in Russian literary and wartime history, NPR notes. According to recent polls, as reported by Voice of America, a majority of Russians regard Crimea as part of Russia.
It is also the only Ukrainian region with an ethnic Russian majority, with ethnic Ukrainians and Tatars making up the rest of the population of 2 million.
Ethnic Russians in Crimea fear anti-Russian sentiment in post-Yanukovych Ukraine.
Ukraine's protesters despised the ousted president's corruption as much as his shift from Europe to Russia, but even so, resentment of Russia's influence in the country played a role in the uprising. Ethnic Russians fear reprisals, especially from Ukraine's far-right groups, and in Crimea, they are forming armed units for self-defense.
Others are troubled that the Ukrainian parliament has overturned a law allowing Russian as a second official language in states where it is spoken by over 10 percent of the population, RT reports.
While it is illegal to promote separatism in Ukraine, Crimean proponents of closer ties to Moscow and more autonomy are taking advantage of Ukraine's turmoil to push their cause, according to Radio Free Europe.
Crimea's Tatar population fear greater Russian influence.
Crimea's Muslim Tatars, around 12 percent of the population, are fiercely opposed to any extension of Russian influence in the region, after a painful history under the Soviet Union.
Having regained Crimea from Nazi control in World War II, Stalin deported the entire Tatar population in the 1940s, accusing them of collaboration. Many died in the aftermath of the expulsion, and Tatars weren't able to return to Crimea until the 1980s.
Russia wants to protect its strategic position in Crimea.
Meanwhile, Russia is stinging from Yanukovych's ouster and is anxious about losing leverage in Ukraine's politics. Crimea is of particular strategic importance as the home of Russia's Black Sea fleet since Soviet times. Its naval presence at the Crimean port Sevastopol was extended until 2042 under Yanukovych.
On Wednesday, the Russian government announced measures to tighten security at its Crimean naval base, after putting military forces on alert around the country.
Most experts say Russia is unlikely to stage a military intervention in Crimea, and many in the Kremlin are cautious of overreaching by embracing Crimean separatism. But Russian President Vladimir Putin seems to be getting ready to act, just in case.