Pro-Russian armed men gather inside the regional government headquarters in Luhansk
Pro-Russian armed men gather inside the regional government headquarters in Luhansk, eastern Ukraine, April 30, 2014. Hundreds of pro-Moscow separatists stormed government buildings in one of Ukraine's provincial capitals on Tuesday and opened fire on police holed up in a regional headquarters, a major escalation of their revolt despite new Western sanctions on Russia. REUTERS/Vasily Fedosenko (UKRAINE - Tags: POLITICS CIVIL UNREST)
Pro-Russian armed men gather at the entrance to the regional government headquarters in Luhansk
Pro-Russian armed men gather at the entrance to the regional government headquarters in Luhansk, eastern Ukraine, April 30, 2014. Hundreds of pro-Moscow separatists stormed government buildings in one of Ukraine's provincial capitals on Tuesday and opened fire on police holed up in a regional headquarters, a major escalation of their revolt despite new Western sanctions on Russia. REUTERS/Vasily Fedosenko (UKRAINE - Tags: POLITICS CIVIL UNREST)
Pro-Russian activists gather at a barricade outside the regional government headquarters in Luhansk
Pro-Russian activists gather at a barricade outside the regional government headquarters in Luhansk, eastern Ukraine, April 30, 2014. Hundreds of pro-Moscow separatists stormed government buildings in one of Ukraine's provincial capitals on Tuesday and opened fire on police holed up in a regional headquarters, a major escalation of their revolt despite new Western sanctions on Russia. REUTERS/Vasily Fedosenko (UKRAINE - Tags: POLITICS CIVIL UNREST)
Pro-Russian armed men stand guard at a checkpoint on the outskirts of Slaviansk
Pro-Russian armed men stand guard at a checkpoint after pro-Russian activists set tires on fire when Ukrainian soldiers arrived on armoured personnel carriers, on the outskirts of Slaviansk, eastern Ukraine April 30, 2014. REUTERS/Baz Ratner (UKRAINE - Tags: POLITICS CIVIL UNREST)
Pro-Russian armed men stand guard at a checkpoint as burning tires are seen in the foreground on the outskirts of Slaviansk
Pro-Russian armed men stand guard at a checkpoint as burning tires set on fire by pro-Russian activists after Ukrainian soldiers on armoured personnel carriers arrived are seen in the foreground on the outskirts of Slaviansk, eastern Ukraine April 30, 2014. REUTERS/Baz Ratner (UKRAINE - Tags: POLITICS CIVIL UNREST)
Pro-Russian armed men stand guard at a checkpoint as burning tires are seen in the foreground on the outskirts of Slaviansk
Pro-Russian armed men stand guard at a checkpoint as burning tires set on fire by pro-Russian activists after Ukrainian soldiers on armoured personnel carriers arrived are seen in the foreground on the outskirts of Slaviansk, eastern Ukraine April 30, 2014. REUTERS/Baz Ratner (UKRAINE - Tags: POLITICS CIVIL UNREST)
A pro-Russian armed man stands guard at a checkpoint as firefighters extinguish burning tires on the outskirts of Slaviansk
A pro-Russian armed man stands guard at a checkpoint as firefighters extinguish burning tires set on fire by pro-Russian activists in the background after Ukrainian soldiers on armoured personnel carriers arrived at the checkpoint, on the outskirts of Slaviansk, eastern Ukraine April 30, 2014. REUTERS/Baz Ratner (UKRAINE - Tags: POLITICS CIVIL UNREST)
A firefighter extinguishes burning tires set on fire by pro-Russian activists at the checkpoint on the outskirts of Slaviansk
A firefighter extinguishes burning tires set on fire by pro-Russian activists after Ukrainian soldiers on armoured personnel carriers arrived at the checkpoint on the outskirts of Slaviansk, eastern Ukraine April 30, 2014. REUTERS/Baz Ratner (UKRAINE - Tags: POLITICS CIVIL UNREST)
Fire fighters extinguish burning tires set on fire by pro- Russians activists at a check point in Slaviansk , east Ukraine
Firefighters extinguish burning tires set on fire by pro-Russian activists after Ukrainian soldiers on armoured personnel carriers arrived at a checkpoint on the outskirts of Slaviansk, eastern Ukraine April 30, 2014. REUTERS/Baz Ratner (UKRAINE - Tags: POLITICS CIVIL UNREST)