A communist supporter takes part in a May Day rally in the eastern Ukrainian city of Kharkiv
A communist supporter takes part in a May Day rally in the eastern Ukrainian city of Kharkiv, May 1, 2014. REUTERS/Konstantin Chernichkin (UKRAINE - Tags: POLITICS CIVIL UNREST)
A Communist supporter stands near a police line guarding the regional administration building during a May Day rally in the eastern Ukrainian city of Kharkiv
A Communist supporter stands near a police line guarding the regional administration building during a May Day rally in the eastern Ukrainian city of Kharkiv, May 1, 2014. REUTERS/Konstantin Chernichkin (UKRAINE - Tags: POLITICS CIVIL UNREST TPX IMAGES OF THE DAY)
Communist supporters take part in a May Day rally in the eastern Ukrainian city of Kharkiv
Communist supporters take part in a May Day rally in the eastern Ukrainian city of Kharkiv, May 1, 2014. REUTERS/Konstantin Chernichkin (UKRAINE - Tags: POLITICS CIVIL UNREST)
Communist supporters take part in a May Day rally in the eastern Ukrainian city of Kharkiv
Communist supporters take part in a May Day rally in the eastern Ukrainian city of Kharkiv, May 1, 2014. REUTERS/Konstantin Chernichkin (UKRAINE - Tags: POLITICS CIVIL UNREST)
Portraits of Ukrainian officials burn outside the prosecutor's office in Donetsk
Portraits of Ukrainian officials burn outside the prosecutor's office in Donetsk May 1, 2014. Pro-Russian protesters stormed the prosecutor's office in the separatist-held city of Donetsk on Thursday, lobbing stones and smashing windows after accusing the office of working for the Western-backed government in Kiev. REUTERS/Marko Djurica (UKRAINE - Tags: POLITICS CIVIL UNREST)
Portraits of Ukrainian officials burn outside the prosecutor's office in Donetsk
Portraits of Ukrainian officials burn outside the prosecutor's office in Donetsk May 1, 2014. Pro-Russian protesters stormed the prosecutor's office in the separatist-held city of Donetsk on Thursday, lobbing stones and smashing windows after accusing the office of working for the Western-backed government in Kiev. REUTERS/Marko Djurica (UKRAINE - Tags: POLITICS CIVIL UNREST)
Pro-Russia activists stand guard with shields at the entrance of the prosecutor's office in Donetsk
Pro-Russia activists stand guard with shields at the entrance of the prosecutor's office in Donetsk May 1, 2014. Pro-Russian protesters stormed the prosecutor's office in the separatist-held city of Donetsk on Thursday, lobbing stones and smashing windows after accusing the office of working for the Western-backed government in Kiev. REUTERS/Marko Djurica (UKRAINE - Tags: POLITICS CIVIL UNREST)
A Pro-Russia activist wearing a riot police helmet and a stick shouts slogans outside the prosecutor's office in Donetsk
A Pro-Russia activist wearing riot a police helmet and a stick shouts slogans outside the prosecutor's office in Donetsk May 1, 2014. Pro-Russian protesters stormed the prosecutor's office in the separatist-held city of Donetsk on Thursday, lobbing stones and smashing windows after accusing the office of working for the Western-backed government in Kiev. REUTERS/Marko Djurica (UKRAINE - Tags: POLITICS CIVIL UNREST)
A Pro-Russia activist wearing a riot police helmet shouts slogans outside the prosecutor's office in Donetsk
A Pro-Russia activist wearing a riot police helmet shouts slogans outside the prosecutor's office in Donetsk May 1, 2014. Pro-Russian protesters stormed the prosecutor's office in the separatist-held city of Donetsk on Thursday, lobbing stones and smashing windows after accusing the office of working for the Western-backed government in Kiev. REUTERS/Marko Djurica (UKRAINE - Tags: POLITICS CIVIL UNREST)
Pro-Russia activists wearing riot police helmets and shields stand guard at the entrance of the prosecutor's office in Donetsk
Pro-Russia activists wearing riot police helmets and shields stand guard at the entrance of the prosecutor's office in Donetsk May 1, 2014. Pro-Russian protesters stormed the prosecutor's office in the separatist-held city of Donetsk on Thursday, lobbing stones and smashing windows after accusing the office of working for the Western-backed government in Kiev. REUTERS/Marko Djurica (UKRAINE - Tags: POLITICS CIVIL UNREST)