East Ukraine protesters joined by miners on the barricades
Coalmining is a major industry in the Donetsk region, which has close ties to Russia
Word spread quickly through the few hundred pro-Russian protesters in Donetsk in eastern Ukraine: "The miners are coming!"
The crowd parted as a group of a dozen or so burly men in orange work helmets marched past barbed-wire and tyre barricades into the 11-storey administration building, which protesters seized last weekend as they demanded greater independence from Kiev.
"Glory to the miners!" the crowd began chanting. "Glory to Donbass!" they shouted, much as protesters at Kiev's Euromaidan demonstrations had shouted "Glory to Ukraine!" before they ousted the president, Viktor Yanukovych, in February.
Donetsk is the heart of eastern Ukraine's coalmining country, historically known as the Donbass, and its football club is called the Miners. Cultural and economic ties to Russia – about three-quarters of people in the Donetsk region speak Russian as their native language – have put the Donbass on a collision course with the new government in Kiev, which plans to sign an association agreement with the EU. Yanukovych is from Donetsk and many here still call him the legitimate president.
Collisions were spreading across eastern Ukraine on Saturday night. Armed separatists seized government buildings in Slaviansk and set up barricades on the outskirts of the city in what Kiev described as an "act of aggression by Russia". The developments have increased concerns of a possible "gas war" that could disrupt energy supplies across the continent.
Militants also took control of the police headquarters in Kramatorsk, 95 miles from the Russian border, after a firefight. Video footage showed an organised unit of more than 20 men wearing matching military fatigues and taking orders from a commander while shooting automatic rifles as they approached the building.
The White House said it will send Vice President Joe Biden to Kiev on April 22 to demonstrate high-level US support for Ukraine after expressing concern about escalating tensions in the eastern part of the country.
Back at the Donetsk occupation, the hundreds of supporters who have gathered each day are a small number of the city's nearly one million residents. But if the 100,000-plus employees of coalmining enterprises were to rise en masse, that would change the political picture drastically, in a similar fashion to the Donbass miners' strikes that helped bring about the breakup of the Soviet Union.