DONETSK, Ukraine — Ukraine government forces on Wednesday recaptured a southeastern town that had been held by separatist rebels, the Interior Ministry said.
There were no casualties in the operation in the town of Svyatogorsk, according to an statement posted on the ministry's website.
The ouster of the rebels was a welcome strategic gain by the Kiev government in the troubled Donetsk region, close to Ukraine's eastern border with Russia.
"The recapture of Svyatogorsk is an indication that the anti-terrorist operation, which experienced certain problems last week, is now gaining momentum," said Dmitry Tymchuk, head of Kiev-based Center for Military and Political Research. "It finally appears that our law enforcement units in the Donetsk region have finally got their act together."
Tymchuk noted that reports suggest that the presence of Russian armed agents in the region was abating.
"We can't with all certainty say whether they are being moved back to Russia or to the neighboring regions of Ukraine," Tymchuk said.
A rebel leader who had declared himself mayor of the nearby town of Slovyansk offered a somewhat contradictory rebuttal to the government's assertion that it had repelled armed separatists.
"It is a propaganda lie because they didn't push anybody out of Svyatogorsk as our forces were not there today," said Vyacheslav Ponomaryov. Nonetheless, he said, "We are quite prepared for their attack and will give them such a welcome they will never forget."
Ponomaryov also acknowledged that his armed group was holding 10 people hostage, among them Ukrainian activists and journalists and one U.S. journalist, Simon Ostrovsky, with Vice News, who was abducted by gunmen in Slovyansk the previous day.
"These Ukrainian guys and this American are not really journalists but provocateurs and they will stay here until we exchange them for our comrades put in prison by the illegal government in Kiev," Ponomaryov said. "I am warning that if we are attacked none of [the hostages] survives."
The Ukraine government alleges that Russian military intelligence agents were behind the seizure of government institutions in Slovyansk, about 80 miles north of Donetsk, the stronghold of armed separatists in the region.
The new developments Wednesday came as Russia threatened to move armed forces into southeastern Ukraine.
"If our lawful interests and interests of Russian people are subjected to a direct threat ... I don't see any other option but to respond within the norms of international law," Russian Foreign Minister Sergei Lavrov said in an interview with Russia Today, an English-language Kremlin-sponsored television network. "An attack on Russian citizens is an attack on Russia."
Ukraine again demanded that Russian troops be withdrawn from areas close to its border.
"The further concentration of Russian troops at the border with Ukraine ... poses a real threat to the worsening of the situation in the east of Ukraine," says a statement on the Foreign Ministry website. "There is a danger that an armed group of pro-Russia forces in this part of Ukraine will use the factor of Russian troops' presence near the border to provoke their entry to the territory of Ukraine."
Special correspondent Victoria Butenko in Kiev contributed to this report.