SLOVYANSK, Ukraine — Ukraine's authorities plan to launch a "full-scale anti-terrorist operation" involving the Army against pro-Russian separatist militants, the acting president said on Sunday.
Oleksandr Turchynov said in a televised address to the nation that Russia was waging a war against Ukraine by sowing disorder in the east of the country, but he offered not to prosecute any militants who gave up their weapons by Monday morning.
Referring to the death of a state security officer and the wounding of other members of law-enforcement bodies in an earlier clash with pro-Russian militants near the town of Slovyansk, he said: "The blood of Ukrainian heroes has been shed in a war which the Russian Federation is waging against Ukraine.
"The aggressor has not stopped and is continuing to sow disorder in the east of the country," he said, referring to a rash of attacks on state buildings by pro-Russian militants in towns in Russian-speaking areas of the east.
Kiev authorities say the separatist rebellions have been inspired and directed by the Kremlin, a charge Moscow denies.
"The National Security and Defense Council has decided to launch a full-scale anti-terrorist operation involving the armed forces of Ukraine," he declared.
"We will not allow Russia to repeat the Crimean scenario in the eastern regions of the country," he said, referring to Moscow's annexation of the peninsula following its takeover by pro-Russian militants.
In Slovyansk on Sunday, Ukrainian special forces exchanged gunfire with a pro-Russia militia, with at least one security officer killed and five others wounded. It was the first reported gun battle in eastern Ukraine.
Interior Minister Arsen Avakov said in a Facebook post that a security service officer was killed in Slovyansk, where the police station and the security service office were seized a day earlier by camouflaged armed men. He also reported a number of casualties among the militia, but did not offer a number.
A reporter found a bullet-ridden SUV on the side of the road and a pool of blood on the passenger seat where the gun battle was supposed to have taken place.
Vladimir Kolodchenko, a lawmaker from the area who witnessed the attack, said a car with four gunmen pulled up on the road in a wooden area outside Slovyansk and opened fire on Ukrainian soldiers who were standing beside their vehicles. Both attackers and the Ukrainian servicemen left soon after the shooting.
Unrest has spread to several municipalities in eastern Ukraine, including the major industrial city of Donetsk, which has a large Russian-speaking population.
Donetsk was also the support base for Viktor Yanukovych, the Ukrainian president ousted in February following months of protests in Kiev that were ignited by his decision to back away from closer relations with the European Union and turn toward Russia. Ethnic Russians in Ukraine's east widely fear that the new pro-Western Ukrainian government will suppress them.
The regional administration in Donetsk issued a statement confirming one dead and saying nine were wounded. It did not identify them, but said one person was shot outside Slovyansk.
Avakov has described the unrest as "Russian aggression."
Ukraine's Foreign Ministry issued a statement late Sunday afternoon accusing "the Russian special service and saboteurs" of fomenting unrest and pledged to present "concrete evidence" of Russia's involvement at next week's planned Ukraine summit in Geneva.
In an earlier post, Avakov said the separatists who had seized the buildings in Slovyansk had opened fire on Ukrainian special forces sent to the city on Sunday. He called on residents to remain calm and stay at home.
A reporter saw no signs of any shots fired at the police station, which was surrounded by a reinforced line of barricades. Unlike on Saturday, the men patrolling the barricades were largely unarmed. One of the guards who asked not to be identified denied reports of fighting at the police station.
Armed camouflaged men were guarding a checkpoint at the main entrance into the city.
Ukrainian lawmaker Oleh Lyashko said Sunday afternoon that Ukrainian forces managed to take control of the city hall, the security service's branch and the police station in Slovyansk. This could not be immediately verified.
Two rival rallies in another regional capital in eastern Ukraine, Kharkiv, turned violent on Sunday. At the end of both rallies, a group of pro-Russian protesters followed several pro-Ukrainian activists, beating them with bats and sticks, Interfax Ukraine reported. A video on Espresso TV showed one activist with blood on his head and hands waiting for paramedics on the steps of the underground passage. Several men and women came up to him and started kicking him.
Kharkiv authorities said that 10 people were injured at the rallies, Interfax reported
In Slovyansk, the mayor said Saturday that the men who seized the police station were demanding a referendum on autonomy and possible annexation by Russia. Protesters in other eastern cities have made similar demands after a referendum in Crimea last month in which voters opted to split off from Ukraine, leading to annexation by Russia.
Overnight, the interior minister reported an attack on a police station in the nearby city of Kramatorsk. A video from local news website Kramatorsk.info showed a group of camouflaged men armed with automatic weapons storming the building. The news website also reported that supporters of the separatist People's Republic of Donetsk have occupied the administration building, built a barricade with tires around it and put a Russian flag nearby.
Regional news website OstroV said three key administrative buildings have been seized in another city in the area, Enakiyeve. In Mariupol, a city south of Donetsk on the Azov Sea and just 50 kilometers away from the Russian border, the city hall was seized by armed masked men. Local news website 0629.com.ua said 1,000 protesters were building a barricade around it while unknown armed men raised the Russian flag over the building.
Material from Reuters is included in this report.