DONETSK, Ukraine — Pro-Russian insurgents driven out of their key stronghold in eastern Ukraine have converged on the major industrial city of Donetsk, where their commander said Sunday that they will regroup to renew their fight against the Ukrainian government.
Ukrainian troops on Saturday forced the rebels out of Slovyansk, a city of about 100,000 that had been the center of the fighting. The success there suggests that the government may finally be making gains in the months-long battle against the insurgency.
It was not yet clear, however, whether the capture of Slovyansk has permanently crippled the rebels.
Rebel fighters from Slovyansk and other towns taken over by the Ukrainian army were seen Sunday milling around central Donetsk, the provincial capital of a region with a population of about 1 million where the separatists have declared independence in the name of the Donetsk People's Republic.
The insurgents control the regional administration building and move freely about the city center, but an attempt in late May to take control of the Donetsk airport was repelled by Ukrainian forces after a furious battle that left dozens of rebel fighters dead.
Igor Girkin, the defense minister of the separatist republic, said in a video interview Sunday with the Russian television channel Life News that he had arrived in Donetsk from Slovyansk.
"We will continue the combat operations and will try not to make the same mistakes that we made in the past," said Girkin, a Russian also known by his nom de guerre, Igor Strelkov. Ukrainian authorities identify him as a veteran of the Russian military intelligence agency.
Nina Yakovleva, a 45-year-old accountant and resident of Donetsk, said she expected nothing good to come of the convergence of rebels in the city.
"We are afraid that Donetsk will be left in ruins like Slovyansk," she said. "The rebels have brought us war and fear."
Pro-Russian insurgents also have been fighting Ukrainian troops in the neighboring Luhansk region, which like Donetsk sits along the border with Russia.