(Reuters) - Here's what you need to know about the Ukraine crisis right now:
HEADLINES
* Ukrainian forces battled Russian invaders on three sides on Thursday after Moscow mounted an assault by land, sea and air.
* By nightfall, a picture was emerging of fierce fighting across multiple fronts. An adviser to the Ukrainian presidential office said Russian forces had captured the Chernobyl nuclear power plant. Heavy exchanges of fire were also taking place in the regions of Sumy and Kharkiv in the northeast and Kherson and Odessa in the south.
* Ukraine's Health Minister Oleh Lyashko said 57 people had been killed and 169 wounded on Thursday.
* Russian President Vladimir Putin said his aim was to demilitarise and "denazify" Ukraine.
* Ukrainian President Volodymyr Zelenskiy said a new iron curtain was falling and closing Russia off from the civilised world. "Our national task is to make sure this curtain does not fall across our land."
* U.S. President Joe Biden said Putin's action was about naked aggression. He unveiled harsh new sanctions, imposing measures to impede Russia's ability to do business in the world's major currencies along with sanctions against major banks and state-owned enterprises.
* British Prime Minister Boris Johnson unveiled a package of "severe" sanctions against Russia targeting banks, members of Putin's closest circle and the extremely wealthy who enjoy high-rolling London lifestyles.
* European Union leaders said sanctions would include freezing Russian assets in the 27-nation bloc, halting banks' access to European financial markets and hitting "Kremlin interests". Moscow would respond with "tit-for-tat" measures, a foreign ministry spokeswoman said.
* Several thousand Ukrainians have crossed into neighbouring countries, mainly Moldova and Romania, while an estimated 100,000 have fled their homes, the U.N. refugee agency said.
* European countries began preparing to receive them.
* Russian police detained more than 1,400 people at anti-war protests in 51 cities according to the OVD-INFO protest monitor.
* Stock markets tumbled. Russia's rouble hit an all-time low.[FRX/]
* The global finance sector was struggling to respond to the invasion, with share prices suffering heavy falls.
* Major buyers of Russian oil were struggling with bank guarantees, according to sources.
QUOTES
- "I have decided to conduct a special military operation... to protect people who have been subjected to bullying and genocide," Putin said. "We will strive for the demilitarisation and denazification of Ukraine."
- "Russia has embarked on a path of evil, but Ukraine is defending itself & won't give up its freedom," Zelenskiy said.
- "Putin is the aggressor. Putin chose this war. And now he and his country will bear the consequences," Biden said.
COMING EVENTS
* The U.N. Security Council is likely to vote on Friday on a draft resolution condemning Russia for invading Ukraine and requiring it to unconditionally withdraw, a senior U.S. administration official said.
* NATO will hold an emergency summit on Friday.