Pro-Russian insurgents in eastern Ukraine have moved to regional capital Donetsk after the government's forces captured their previous strongholds in the cities of Slovyansk and Kramatorsk over the weekend.
Rebel leader Igor Girkin confirmed the loss of the two cities in a video interview posted Saturday on the website of the insurgency's press service, Ikorpus.ru.
The separatists managed to break through the enemy encirclement, also evacuating fighters' families, though that required a suicide rearguard action by an armored unit, Girkin said.
The retreat was intended to spare civilians in the recaptured cities from the heavy shelling by Ukrainian forces, said Girkin, a Russian citizen who uses the alias "Colonel Strelkov."
Slovyansk and Kramatorsk have a population of 118,000 and 165,000 respectively. Donetsk, the rebels' new base, has a population of 1 million.
The rebels are fortifying positions in Donetsk, which is likely to see military action, Donetsk region's pro-Ukrainian governor Serhiy Taruta said Sunday, Hromadske.tv news website reported.
Ukrainian President Petro Poroshenko called the capture of Slovyansk and Kramatorsk "a turning point in the struggle for the territorial integrity of Ukraine," but said he was "far from euphoric."
"My order stands — continue encircling the terrorists and the operation to liberate the Donetsk and Luhansk regions," Poroshenko said Saturday, according to his official website.
The government's forces would not bomb Donetsk and Luhansk, another insurgency center with a population of 420,000, a representative of the National Security and Defense Council of Ukraine said Sunday.
The Ukrainian Army provided food relief to residents of Slovyansk and Kramatorsk and has begun rebuilding infrastructure damaged by the fighting, the command center of the anti-insurgency mission said on its Facebook page on Sunday.
A rebel spokesman was cited by the ITAR-Tass news agency as saying on Sunday that mass arrests were taking place in the two recaptured cities. Ukrainian authorities did not comment on the allegations.
A separatist uprising has been building steam in the Donetsk and Luhansk regions since February. The rebels have proclaimed the independence of the two regions and asked to join Russia, which has ignored their request.
The Ukrainian Army began a successful offensive against rebels after the May presidential elections, which brought Poroshenko to power, who pledged to suppress the uprising.
Girkin said on Thursday he expected the outnumbered and outgunned insurgency to be defeated before July 12, according to Ikorupus.ru.
The United Nations estimated last month that 423 people, both fighters and civilians, were killed in eastern Ukraine between mid-April and June 20. More than 34,000 were displaced by the fighting.