U.S. State Department warns of stepped up Russian attacks in Ukraine

The U.S. State Department warns that Russia is preparing to step up attacks on Ukrainian cities in response to a brazen car bomb attack that killed the daughter of one of President Vladimir Putin’s closest advisers. The Kremlin blames the attack on Kyiv – but exiled Russian MP Ilya Pomoronev tells CBS News’ Debora Patta it was the work of an underground resistance group working inside Russia.