Ukraine's heavily Russified southeast has been the scene of a string of uprisings and attacks by pro-Russian armed groups since April 6.
The main unrest has focused around Donetsk, Lugansk and Kharkiv, the regional centres of an economically depressed rust belt that stretches along the border with Russia.
In Donetsk, a city of one million inhabitants and the secessionist hotspot, demonstrators stormed the government building on April 6, and are still holed up there. On April 7 they proclaimed the "Donetsk People's Republic" and vowed to hold a referendum on joining Russia.
In the surrounding region, pro-Russian gunmen dressed in camouflage uniforms and balaclavas took over the police station and local security services building Saturday in Slavyansk (100 kilometres, 60 miles north of Donetsk).
On the same day, in Kramatorsk (70 kilometres, 45 miles north of Donetsk), masked and uniformed gunmen armed with Kalashnikovs attacked the police and municipal headquarters.
In Lugansk, an industrial city of 400,000 people, armed pro-Russian militants forced their way into and occupied a building belonging to Ukraine's SBU security services on April 6. They demanded that separatist leaders arrested days earlier be released. They have since dug in despite the rising risk of an assault to dislodge them.
In the main eastern city, which has 1.5 million inhabitants, clashes erupted on April 6 between more than 2,000 pro-Russian protesters who took over the offices of the regional governor and nationalists loyal to Kiev. A day later they were made to leave the building. Three days of riots followed. On Sunday, demonstrations unsuccessfully tried to enter the town administration headquarters.