Mstyslav Chernov, AP
A pro-Russian armored vehicle moves toward Slovyanoserbsk, eastern Ukraine, Wednesday, Jan. 21, 2015.

DNIPROPETROVSK, Ukraine — Ukrainian officials said Thursday that their forces have retreated from the main portion of the airport at Donetsk, a key turning point in an eight-month battle with Russian separatist forces that has turned the facility into a hulk of twisted metal and shattered glass.

“Taking into account the danger and in order to save lives, ... it was decided yesterday to move out of the terminal’s territory and to the new lines,” Vladyslav Seleznyov, spokesman for the Ukrainian Armed Forces, said at a briefing.

The airport, strategically located on a hilltop about six miles outside of the city of Donetsk, has been the scene of fierce fighting for months as Ukrainian forces battled Russia-backed separatists for what both sides regard as a key symbol for control of the contested region of eastern Ukraine.

The terminal of the gleaming new airport, upgraded in 2012 for the European soccer championships, has been reduced to ruins; the control tower has collapsed, and the runways have been pocked with shelling. But analysts say the airport could eventually provide a key supply line into the region.

Its capture marks the first important territorial advance for Russian separatists since a cease-fire — often ignored — was signed in September.

More than 4,800 people have been killed and at least 1.2 million others displaced since pro-Russia rebels seized parts of the Luhansk and Donetsk regions in April.

At least six Ukrainian service members were killed during a final battle for control of the airport on Wednesday, officials said.

Several soldiers were wounded in the collapse of part of the airport structure earlier this week, and a number of others were taken prisoner by the separatists when they attempted to rescue the wounded, Ukrainian officials said.

“Sixteen Ukrainian servicemen who were concussed in the fight for the airport, were taken captive by the militants of the so-called DPR (the self-proclaimed Donetsk People’s Republic),” Seleznyov said at the briefing. “Negotiations about their liberation are currently underway.”

Ukrainian officials said the last, intense battle for control of the airport has raged for nearly a week. Their forces continued to remain stationed not far away from the facility.

“For six days we were desperately trying to regain control of the new terminal but failed,” presidential aide Yuri Biryukov said in an interview. “At the same time the airport continues to remain the battle field and the front line.”

“We are 700 meters (about half a mile) away from the (new) terminal,” one Ukrainian defender wrote in a message to The Times on Wednesday. “There is nothing left there. Only our 200-s,” (Soviet-era military slang term for those killed in action).

The battle for the airport started on May 26 when a force of Ukrainian paratroopers stormed the airport, reportedly killing dozens of Russian mercenaries from Chechnya.

“The defense of the airport is our little Stalingrad,” Yuri Butusov, a defense expert and head of the online publication Censor.net told The Times, referring to one of the most devastating battles of World War II in which Soviet forces successfully defended that city against Germany.

“It is a great symbol that the Ukrainian army and Ukrainian people can resist the Russian invasion and defend their land heroically,” he said.