Tens of thousands took part in rival pro-unity and pro-Russian rallies in Ukraine on Sunday ahead of a planned secession referendum in Russian-occupied Crimea. Crimea is set to vote this Sunday on whether to break off from Ukraine and join Russia following the ouster of Ukrainian President Viktor Yanukovych last month. In a show of support for the new government, the White House has announced President Obama will host newly installed Ukrainian Prime Minister Arseniy Yatsenyuk at the White House this week. We’ll have more from Ukraine after headlines.