Vladimir Putin has overseen annual exercises by Russia's nuclear forces.<br /><br />Ballistic and cruise missiles were launched from the Arctic to Russia's Far East, the Kremlin said.<br /><br />The US was told about the drill under the terms of the New Start arms treaty.<br /><br />The launches took place as Russia made unsubstantiated claims that Ukraine was plotting to use a "dirty bomb" - an explosive device mixed with radioactive material.<br />
