Pro-Russian gunmen seized buildings in eastern Ukraine , as new flashpoints developed in the ongoing crisis over the region 's future . As tensions rose , acting President Oleksandr Turchinov held an emergency National Defense and Security Council meeting Saturday evening in the capital Kiev , according to the President 's press office . In the eastern city of Kramatorsk , police and pro-Russia activists exchanged gunfire , acting Interior Minister Arsen Avakov 's spokeswoman , Natalia Stativko , told CNN on Saturday . Slightly north , in the town of Slaviansk , gunmen in camouflage stormed and seized a police building early Saturday , authorities said . They arrived in two mini-buses , came to the police station and opened fire at the building before getting inside the facility through windows , the Donetsk regional police press office said . Three police officers were slightly injured . The gunmen introduced themselves as part of the Donetsk republic initiative group , police said . Their goal was to seize hundreds of weapons inside the police building ; they allowed the police officers inside to leave the facility , the press office said . A CNN team in Slaviansk saw dozens of armed , well-equipped men in camouflage in control of the Ukraine Security Services ( SBU ) building , as well as the police building . The men did not want to be filmed . Makeshift barricades have been erected around both buildings . Locals brought food and tires to the armed men at the SBU site . `` We 're for democracy , for the rights of the people to express their will , '' one pro-Russian armed activist in Slaviansk told Reuters . `` We want to create a people 's republic , a real one , one in Donetsk , one in Luhansk , and in general let the people of the southeast determine what they want . We want to hold a referendum . '' A police building in the town of Krasni Liman also had been taken by protesters , according to Stativko , the spokeswoman for Ukraine 's acting interior minister , although the CNN team saw no evidence to that effect . Special units are being sent to both Slaviansk and Krasni Liman to assess the situation , she said . Donetsk chief of regional police resigns . The latest reports come amid heightened tensions in the country 's largely Russian-speaking eastern region , centered on the cities of Donetsk , Luhansk and Kharkiv . Pro-Russian protesters in those cities seized government buildings several days ago and remain barricaded in some . In Donetsk , the chief of regional police has resigned . Kostyantyn Pozhydaev announced his resignation during a pro-Russia activist rally outside the police office , the Donetsk regional police press office said in a statement Saturday . Earlier Saturday , the acting Ukrainian President 's website stated that the Head of the Security Service for the Donetsk region , Valery Ivanov , was sacked . A demonstration was held in front of the Donetsk police headquarters Saturday , according to the interior ministry . Although life in most of the city continues as normal , protesters still hold government buildings . Prime Minister Arseniy Yatsenyuk paid a visit to Donetsk on Friday as he seeks to rally those in the region -- which has strong ties to Russia -- behind the interim government in Kiev ahead of elections due on May 25 . He suggested that constitutional reform could give more power to the regions , though the time frame is short . `` We almost do n't have time to amend the constitution before the presidential election , '' he said , adding that they need to move fast so that any new president does n't dictate terms . The United States has accused Russia of fomenting the separatist unrest in its neighbor as a pretext for military intervention . White House expresses concern , Kerry speaks to Lavrov . U.S. Secretary of State John Kerry spoke by phone with Russian Foreign Minister Sergey Lavrov Saturday , expressing `` strong concern that attacks today by armed militants in eastern Ukraine were orchestrated and synchronized , similar to previous attacks in eastern Ukraine and Crimea , '' a senior State Department official said . The two diplomats had met late last month in Paris to discuss the crisis . The official said that Kerry warned Lavrov there would be `` additional consequences '' if Russia did not take steps to de-escalate the situation in eastern Ukraine and move its troops back from its border with Ukraine . The official also noted that militants involved in Saturday 's unrest in eastern Ukraine `` were equipped with specialized Russian weapons and the same uniforms as those worn by the Russian forces that invaded Crimea . '' The White House also reacted Saturday , calling on Russian President Vladimir Putin and his government to `` cease all efforts to destabilize Ukraine . '' `` We are very concerned by the concerted campaign we see underway in eastern Ukraine today by pro-Russian separatists , apparently with support from Russia , who are inciting violence and sabotage and seeking to undermine and destabilize the Ukrainian state , '' said National Security Council spokeswoman Laura Lucas Magnuson , in a statement . `` We saw similar so-called protest activities in Crimea before Russia 's purported annexation . '' Vice President Joe Biden will travel to Kiev on April 22 , to meet government leaders and members of the civil society . `` The Vice President will underscore the United States ' strong support for a united , democratic Ukraine that makes its own choices about its future path , '' the White House said in a statement . U.S. State Department spokeswoman Jen Psaki , in a tweet , described the situation as `` worrisome . `` Russia again seems to be behind '' the unrest , Psaki said Saturday . Meanwhile , the U.S. Treasury on Friday imposed a third round of sanctions on individuals considered to be involved in Crimea 's annexation . They include six individuals classed by the Treasury as Crimean separatists , former Ukrainian official Sergey Tsekov , and the Crimea-based natural gas company Chernomorneftegaz , which the Treasury says has appropriated assets belonging to Crimea 's state-run gas company . `` Crimea is occupied territory . We will continue to impose costs on those involved in ongoing violations of Ukraine 's sovereignty and territorial integrity , '' said Treasury official David S. Cohen . Diplomatic steps . Next Thursday , EU foreign policy chief Catherine Ashton will meet in Switzerland with foreign ministers from the United States , Russia and Ukraine to discuss efforts to de-escalate the situation . That meeting will follow talks between EU foreign ministers on Monday in Luxembourg . EU defense ministers are also due to meet Tuesday , with the situation in Ukraine high on the agenda . Western powers say they want to resolve the crisis through diplomatic and political means , and have warned of tougher sanctions against Russia if it intervenes further in Ukraine . Ukraine acting Foreign Minister Andriy Deshchytsia and his Russian counterpart , Sergey Lavrov , spoke Saturday by phone to discuss preparations for Thursday 's meeting , Ukraine 's Foreign Ministry said . In the call , Deshchytsia demanded that Russian special services agents end their `` provocative actions '' in eastern Ukraine , which are intended to derail the Geneva meeting and impede efforts to resolve the crisis , the ministry said . Lavrov said Friday in a televised interview on Russian state television that there are no Russian troops or Russian secret services agents in southeastern Ukraine , the official ITAR-Tass news agency reported . He also said Russia has no intention of absorbing the southeastern regions of Ukraine , contrary to the fears of the West . Russia annexed Ukraine 's southeastern Crimea region last month , following a referendum condemned as illegal by Kiev and the international community , and the West fears it may next seek to enter eastern Ukraine .
Secretary of State Kerry speaks to Russian foreign minister . Washington ( Unidentified gunmen seize buildings in the eastern Ukraine town of Slaviansk . Pro-Russian protesters have taken over buildings in other cities in the region in past days .