Ukrainian Forces Take Offensive Against Pro-Russian Separatists

Ukrainian army paratroopers sit atop an armored personnel carrier as they move toward Slovyansk,  June 2, 2014. 

A member of the "Donbass" self-defense battalion trains at a National Guard of Ukraine base, near Kyiv, June 2, 2014. 

Hundreds of armed insurgents attacked a border guard encampment in eastern Ukraine as rebels nearby promised saftety for the officers if they surrendered the base and lay down arms, Slovyansk, June 2, 2014. 

Ukrainian army paratroopers move into position in Slovyansk, Ukraine, June 2, 2014. 

Members of the "Donbass" self-defense battalion train at a National Guard base, near Kyiv, June 2, 2014.

Members of the "Donbass" self-defense battalion train at a National Guard of Ukraine base, near Kyiv, June 2, 2014.

Newly-elected mayor of Kyiv, Vitali Klitschko, chairman of the Ukrainian party Udar (Punch), and the former world heavyweight boxing champion, attends a rally in Independence Square in Kyiv, Ukraine, June 1, 2014. 

Members of self-defense units stand during a minute of silence in honor of people killed in Independence Square during clashes February 18-21 in Kyiv and soldiers killed during anti-terrorist campaigns in the east of Ukraine, Independence Square, Kyiv, June 2, 2014.