Russian troops launched a wide-ranging attack on Ukraine on Thursday, as President Vladimir Putin cast aside international condemnation and sanctions and warned other countries that any attempt to interfere would lead to “consequences you have never seen.” Ukraine’s leadership said at least 40 people have been killed so far in what it called a “full-scale war” targeting the country from the east, north and south.

Ukrainian border guards released footage of what they said were Russian military vehicles moving in, and big explosions were heard in the capital Kyiv, Kharkiv and Odesa. As the Russian military claimed to have wiped out Ukraine’s entire air defenses in a matter of hours, Ukrainians fled some cities and European authorities declared Ukrainian air space an active conflict zone. World leaders decried the start of a long-anticipated invasion with far-reaching consequences, as global financial markets plunged and oil prices soared. Governments from US to Asia and Europe readied new sanctions after weeks of failed efforts for a diplomatic solution, but said they will not intervene militarily to defend Ukraine.