Kiev, April 13 : Pro-Russia militants took over a police headquarters in Ukrainian city of Kramatorsk, BBC reported Saturday citing local media and witnesses.
This followed a gun battle with the police defending the building as the attackers stormed it.
Several other official buildings were reported to have been seized in Donetsk region Saturday.
The confrontations come amid rising tension between the new government and pro-Russia protesters.
Eastern Ukraine has a large Russian-speaking population and has seen a series of protests since the ousting of pro-Russian President Viktor Yanukovych in February.
The new government in Kiev accuses Moscow of orchestrating the unrest in eastern Ukraine. Russia, however, denies being responsible for the situation.
According to CNN, pro-Russian gunmen seized buildings in eastern Ukraine, as new flashpoints developed in the ongoing crisis over the region's future.
Acting President Oleksandr Turchinov held an emergency National Defense and Security Council meeting Saturday evening in Kiev, the President's press office said.
In Kramatorsk city, police and pro-Russia activists exchanged gunfire, acting Interior Minister Arsen Avakov's spokeswoman Natalia Stativko, said Saturday.
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.
These gunmen introduced themselves as part of the Donetsk republic initiative group, police said, adding that their goal was to seize hundreds of weapons inside the police building.
Meanwhile, amid mounting concern about the situation, US Secretary of State John Kerry called his Russian counterpart Sergei Lavrov, BBC reported.
Saying Ukraine was "demonstrating its inability to take responsibility for the fate of the country", Lavrov warned that any use of force against Russian speakers in eastern Ukraine would undermine the "potential for co-operation", which included talks in Geneva next week.
