HORLIVKA, Ukraine — Ukraine's acting president conceded Wednesday that his police and security forces were "helpless" to stifle unrest in the country's east, where pro-Russia gunmen seized more buildings, walking into the police station and mayor's office in this mining hub without resistance.
Insurgents also took control of the customs service building in Donetsk, the region's main city, and city hall in Alchevsk, an industrial center of about 110,000, adding to the scores of buildings taken by the separatists over the past month in the east, where a dozen cities are now in the hands of the separatists.
Acting President Oleksandr Turchynov has twice proclaimed "anti-terrorist" operations to regain control of the east, but to little effect. In a meeting with officials from other Ukrainian regions, he acknowledged the failure and indicated the government would back off even trying to bring the most restive parts of the east to heel, focusing instead on trying to keep the unrest from spreading to other parts of the nation of 46 million.
"I will be frank: Today, security forces are unable to quickly take the situation in the Donetsk and Luhansk regions under control," Turchynov said. "The security bodies ... are unable to carry out their duties of protecting citizens. They are helpless in those matters."
"Moreover, some of those units are either helping or cooperating with terrorist organizations," he said.
Hours after Turchynov spoke, authorities in the capital, Kiev, announced security forces would hold exercises overnight. The maneuvers could be aimed at reassuring Ukrainians that the government was not capitulating. But they are also likely to be seen as an aggressive move by the eastern insurgents, who claim the government is a nationalist cabal intent on suppressing the east's large Russian-speaking population.
Turchynov's government, which came to power after Russia-friendly president Viktor Yanukovych was ousted in the wake of monthslong protests, and its supporters in the West have accused Moscow of orchestrating the turmoil in eastern Ukraine, which borders Russia. The United States and the European Union rolled out new economic sanctions against Russia this week, but Moscow has remained unbowed, denying its role in the unrest.
On Wednesday, Turchynov said "mercenaries and special units" were attacking eastern Ukraine.
"That is why I am stressing our task is to stop the spread of the terrorist threat, first of all in the Kharkiv and Odessa regions," Turchynov was quoted as saying by the Interfax news agency.
Kharkiv is in eastern Ukraine, north of the Donetsk and Luhansk regions that are the heart of the insurgency; Odessa is on the Black Sea coast, about 120 miles (200 kilometers) west of the Crimea peninsula, which Russia annexed in March after its troops backed separatist self-defense forces.
The mayor of Kharkiv, who had been credited with keeping Ukraine's second-largest city calm, was shot in the back while jogging earlier this week.
Turchynov said the threat of a Russian invasion was real and urged the creation of regional self-defense units throughout the country. Russia has placed tens of thousands of troops near the border with Ukraine.
Some Ukrainians were appalled by the loss of control over the country's eastern regions and accused the central government of reacting too slowly.
"In a normal society, when Oleksandr Turchynov admits the fact that the authorities do not control the situation in the east of the country, that's grounds for resignation. And not just from him, but all the security forces," Valeriy Kalnysh, the former editor of the now-defunct Kommersant Ukraine daily, wrote on Facebook. "But can we afford this now? .... And is it the right move in the conditions of an undeclared war with Russia?"
Former prime minister and presidential candidate Yulia Tymoshenko urged Ukrainians to join a resistance force that she was creating that would act in coordination with the army.
"Ukraine is under attack. Russia has begun an undeclared war against our country in the east," Tymoshenko said in a statement Wednesday. "I call upon all patriots who have ever participated in military operations to join us immediately.
Ukraine is holding a presidential election on May 25, and Tymoshenko is among several top candidates.
In eastern Ukraine, meanwhile, insurgents wielding automatic weapons hoisted an insurgent flag above the city council building in Horlivka, a mining and chemical industry hub in the Donetsk region. They also took control of a police station in the city of 250,000, adding to another police building they have controlled for several weeks.
Armed men were guarding the city council building and checking the documents of all those entering it. One guard said foreign reporters would not be allowed in and threatened to arrest those who didn't obey. Similar guards were posted outside the city's police station.
The insurgents who now control buildings in about a dozen cities in eastern Ukraine are demanding broader regional rights as well as greater ties or outright annexation by Russia. The militiamen are holding some activists and journalists hostage, including seven observers from a European security organization.
In Luhansk, one of the largest cities in eastern Ukraine, gunmen in camouflage uniforms maintained control of several government offices they seized Tuesday. In Donetsk, insurgents added the local customs service office to the list of buildings they have seized.
Dzhavad Iskanderov, a member of the insurgents' self-appointed government, told the Associated Press the building was seized to prevent nationalists and other pro-Kiev forces from seizing the weapons inside.
Eastern Ukraine, which has a large Russian-speaking population, was the heartland of support for Yanukovych, who fled to Russia in February. The government that replaced him in Kiev has resisted the insurgents' demands, fearing they could lead to a breakup of the country or more regions being annexed by Russia.