Russia said it has sent about 6,000 troops into Crimea to protect Russian citizens, in addition to pro-Russian militias that were already in Crimea. The Ukraine government claims Russia has sent 16,000 troops into Crimea.
Together they have taken over parliament, the airports, and many government buildings. Troops have also surrounded or taken over many military bases, though not violently.
This morning, unarmed Ukrainians tried to take back one of their bases, but as they approached Russian militia soldiers stationed outside the Russians fired warning shots into the air. A tense standoff ensued for hours until the Ukrainian eventually turned and left.
The Ukraine military still holds five bases plus its naval headquarters in Crimea.
6. The World is Waiting to See What Will Happen Next
Ukraine has mobilized its troops to readiness levels but has not said it will take action against the Russian forces.
Russia has not made any move to go beyond Crimea into the rest of Ukraine.
World leaders will decide on how to respond to Russia's military moves this week, which could include economic sanctions or more serious action.
The AP contributed to this report.