Pro-Russian protesters take part in a rally near the seized office of the SBU state security service in Luhansk
Pro-Russian protesters take part in a rally near the seized office of the SBU state security service in Luhansk, eastern Ukraine, April 27, 2014. Several hundred protesters on Sunday called for the creation of the People's Republic of Lugansk, using the Russian spelling for Luhansk. REUTERS/Vasily Fedosenko (UKRAINE - Tags: POLITICS CIVIL UNREST)
Pro-Russian protesters take part in a rally near the seized office of the SBU state security service in Luhansk
Pro-Russian protesters take part in a rally near the seized office of the SBU state security service in Luhansk, eastern Ukraine, April 27, 2014. Several hundred protesters on Sunday called for the creation of the People's Republic of Lugansk, using the Russian spelling for Luhansk. REUTERS/Vasily Fedosenko (UKRAINE - Tags: POLITICS CIVIL UNREST)
Pro-Russian protesters take part in a rally near the seized office of the SBU state security service in Luhansk
Pro-Russian protesters take part in a rally near the seized office of the SBU state security service in Luhansk, eastern Ukraine, April 27, 2014. Several hundred protesters on Sunday called for the creation of the People's Republic of Lugansk, using the Russian spelling for Luhansk. REUTERS/Vasily Fedosenko (UKRAINE - Tags: POLITICS CIVIL UNREST)
A pro-Russian protester watches through binoculars from a lookout tower during a rally near the seized office of the SBU state security service in Luhansk
A pro-Russian protester watches through binoculars from a lookout tower during a rally near the seized office of the SBU state security service in Luhansk, eastern Ukraine, April 27, 2014. Several hundred protesters on Sunday called for the creation of the People's Republic of Lugansk, using the Russian spelling for Luhansk. REUTERS/Vasily Fedosenko (UKRAINE - Tags: POLITICS CIVIL UNREST)
Pro-Russian protesters take part in a rally near the seized office of the SBU state security service in Luhansk
Pro-Russian protesters take part in a rally near the seized office of the SBU state security service in Luhansk, eastern Ukraine, April 27, 2014. Several hundred protesters on Sunday called for the creation of the People's Republic of Lugansk, using the Russian spelling for Luhansk. REUTERS/Vasily Fedosenko (UKRAINE - Tags: POLITICS CIVIL UNREST)
Pro-Russian protesters take part in a rally near the seized office of the SBU state security service in Luhansk
Pro-Russian protesters take part in a rally near the seized office of the SBU state security service in Luhansk, eastern Ukraine, April 27, 2014. Several hundred protesters on Sunday called for the creation of the People's Republic of Lugansk, using the Russian spelling for Luhansk. REUTERS/Vasily Fedosenko (UKRAINE - Tags: POLITICS CIVIL UNREST)
Pro-Russian protesters take part in a rally near the seized office of the SBU state security service in Luhansk
Pro-Russian protesters take part in a rally near the seized office of the SBU state security service in Luhansk, eastern Ukraine, April 27, 2014. Several hundred protesters on Sunday called for the creation of the People's Republic of Lugansk, using the Russian spelling for Luhansk. REUTERS/Vasily Fedosenko (UKRAINE - Tags: POLITICS CIVIL UNREST)
Pro-Russian activists attend a rally in Donetsk
Pro-Russian activists attend a rally in Donetsk, Eastern Ukraine, April 27, 2014. U.S. President Barack Obama on Sunday said the United States and Europe must join forces to impose sanctions on Russia to stop it destabilising Ukraine, where armed pro-Russian separatists were for a third day holding eight international observers prisoner. REUTERS/Baz Ratner (UKRAINE - Tags: POLITICS CIVIL UNREST)
A pro-Russian activist holds a sign during a rally in Donetsk
A pro-Russian activist holds a sign during a rally in Donetsk, Eastern Ukraine, April 27, 2014. U.S. President Barack Obama on Sunday said the United States and Europe must join forces to impose sanctions on Russia to stop it destabilising Ukraine, where armed pro-Russian separatists were for a third day holding eight international observers prisoner. REUTERS/Baz Ratner (UKRAINE - Tags: POLITICS CIVIL UNREST)