Scores of Russian soldiers are reportedly entering Ukraine through eastern borders amid escalating crisis.
Ukraine has recaptured a small airport previously occupied, says government.
BP chief executive Bob Dudley says BP investments not under threat from Western sanctions.
State security service says unnamed bank transferred millions to militants before takeover
Ukraine's acting president Oleksandr Turchynov has announced the launch of a military operation in the eastern Donetsk region.
European markets were tentative on Tuesday morning as the crisis in Ukraine threatened to escalate further
Best photos of the day: 15 April 2014.
Western leaders are considering more economic sanctions against Moscow after unrest in Ukraine's east.
Ukraine paratroopers carried out military exercises in the Donetsk region, as tensions continue in the east of the country.
Europe is better prepared to deal with a disruption to Russian gas supplies than it was last time
Obama says protesters must surrender their arms, while Putin asks US president to help prevent more bloodshed.
Key meeting between Didier Burkhalter and Ukraine's Arseny Yatsenyuk marred by flag mixup.
UK foreign secretary William Hague has said that there is no doubt that Russia is behind the unrest in eastern Ukraine.
Palladium has outperformed other precious metals this year with a 14% jump in prices.
Prime minister warns that events in eastern Ukraine bear hallmarks of Russian intervention
Ukraine crisis hits British blue chip stocks as pro-Russian militants hold their ground.
Moscow's Strategic Missile Forces conducts ballistic missile test from Plesetsk.
Russian ambassador to the UN Vitaly Churkin put the blame squarely on the west and said it was the responsibility of the western powers to "avert a civil war".
US ambassador to the UN Samantha Power accused Moscow of orchestrating the latest events in Ukraine putting the lives of scores of civilians at risk.
Rising geopolitical tensions over Ukraine sent Brent crude futures above $108 a barrel
Russia and western powers indulge in blame game as Kiev vows to press ahead with full-scale offensive against separatists.
Kiev administration launches "anti-terrorist operation" in eastern Ukrainian cities as helicopters and infantry vehicles are reportedly deployed.