Pro-Russian activists who seized government buildings in the eastern Ukrainian city of Donetsk have proclaimed independence from Ukraine — in an echo of the events which preceded Russia's annexation of Crimea.

donetsk balaclava
Pro-Russian activists man a barricade outside the Donetsk regional council office buildingAFP

The activists have demanded that a referendum be held no later than 11 May on the possible secession of the Donetsk region

Pro-Russian crowds also stormed government buildings in Luhansk and Kharkiv, cities located in Ukraine's predominantly Russian-speaking eastern region.

Ukrainian Prime Minister Arseniy Yatsenyuk accused Russia of being behind the unrest and of seeking to sow instability as a pretext for sending troops across the border.

Riot police and pro-Russian activists clash in Donetsk
Riot police and pro-Russian activists clash in DonetskReuters
Pro-Russian activists scuffle with police near the regional government building in Donetsk
Pro-Russian activists scuffle with police near the regional government building in DonetskReuters
Pro-Russian protesters storm the regional government building in the eastern Ukrainian city of Donetsk
Pro-Russian protesters storm the regional government building in the eastern Ukrainian city of DonetskReuters
Pro-Russia protesters attempt to enter the regional government building in Donetsk through a broken window
Pro-Russia protesters attempt to enter the regional government building in Donetsk through a broken windowReuters
Activists who seized the main administration building in Donetsk wave the Russian flag and the flag of the so-called Donetsk Republic, after they declared the creation of a sovereign
Activists who seized the main administration building in Donetsk wave the Russian flag and the flag of the so-called Donetsk Republic, after they declared the creation of a sovereign "people's republic" independent of Kiev ruleAFP
Activists guard a barricade outside Donetsk's main administrative building
Activists guard a barricade outside Donetsk's main administrative buildingAFP
Masked pro-Russian demonstrators defend their barricade
Masked pro-Russian demonstrators defend their barricadeAFP
Pro-Russian demonstrators keep watch at a barricade built outside the Ukrainian regional Security Service building in Donetsk
Pro-Russian demonstrators keep watch at a barricade built outside the Ukrainian regional Security Service building in DonetskAFP
Pro-Russian activists who seized the main administration building in Donetsk vote to create a sovereign
Pro-Russian activists who seized the main administration building in Donetsk vote to create a sovereign "people's republic" independent of KievAFP
Pro-Russian activists occupy the regional security service building in Lugansk
Pro-Russian activists occupy the regional security service building in LuganskAFP
Pro-Russian protesters clash with activists supporting a united Ukraine in the eastern Ukrainian city of Kharkiv
Pro-Russian protesters clash with activists supporting a united Ukraine in the eastern Ukrainian city of KharkivReuters
Pro-Russian protesters storm the regional administrative building in Kharkiv
Pro-Russian protesters storm the regional administrative building in KharkivReuters
People attend to a man who was injured when pro-Russian protesters stormed the offices of the state security services in Lugansk, eastern Ukraine
People attend to a man who was injured when pro-Russian protesters stormed the offices of the state security services in Lugansk, eastern UkraineReuters
Pro-Russian protesters and police officers surround a group of ultra-nationalist Right Sector group members in Kharkiv. The ultra-nationalists were forced to march down a steep hill on their knees in what appeared to be a humiliation ritual
Pro-Russian protesters and police officers surround a group of ultra-nationalist Right Sector group members in Kharkiv. The ultra-nationalists were forced to march down a steep hill on their knees in what appeared to be a humiliation ritualAFP