Protesters waving Russian flags have seized the regional administrative building in the Ukrainian city of Kharkiv. <br /><br /> It’s the third state premises in eastern Ukraine to be occupied by pro-Russian demonstrators in the space of 24 hours, according to Interfax newsagency. <br /><br /> All three cities lie close to Ukraine’s border with Russia.<br /><br /> Earlier, similar groups seized the offices of the state security services in Luhansk, demanding that regional lawmakers carry out a referendum on joining Russia.<br /><br /> One Russian protester explained: “I want to go home, you understand, I want to see my family in Russia and for that should I need to get a foreign passport to cross the border? To see my aunts, my sisters, my cousins? Who needs that?”<br /><br /> Around 15,000 protesters in the eastern Ukrainian city of Donetsk stormed the regional government building. They replaced the Ukrainian flag on the building with a Russian one.<br /><br /> The protesters who had surrounded the building cheered, chanting “Russia!”