Residents were evacuated from Lyman in early May ahead of advancing Russian troops.
KYIV -- Ukrainian forces have surrounded Russian troops in the area of the crucial rail hub of Lyman, a spokesman for the Ukrainian Eastern Group of Forces has said.
"The Russian group in the Lyman area is surrounded," spokesman Serhiy Cherevatiy said on October 1. "The settlements of Yampil, Novoselivka, Shandryholove, Drobysheve, and Stavky have been liberated and stabilization measures are being taken there."
Video posted on social media appeared to show Ukrainian troops raising the country's flag on the outskirts of Lyman.
Cherevatiy estimated the number of surrounded Russian troops at about 5,000, adding that Russian forces continue to try to break out of the encirclement.
The fierce fighting around the Donetsk region railway hub of Lyman threatens to deal Russia a significant military setback in one of the regions that Russia has illegally claimed as its own territory.
Russia did not comment on the reports.
Moscow has used Lyman as a logistical hub for operations in the northern part of the Donetsk region. Its fall would mark the most serious setback for Russian forces since a lightning Ukrainian counteroffensive sent Russian troops reeling in the Kharkiv region last month.
Cherevatiy added that the liberation of Lyman would enable Ukrainian forces to push into the Luhansk region "toward Kreminna and Syevyerodonetsk."
Such a move would further embarrass the Kremlin, which declared the Luhansk region fully occupied in early July.
"It is psychologically very important," Cherevatiy said, emphasizing that "the operation is not yet over."
Russian President Vladimir Putin on September 30 illegally proclaimed the partially occupied Ukrainian regions of Luhansk, Donetsk, Kherson, and Zaporizhzhya as Russian territory, a significant political escalation that was broadly condemned by the West.
The four regions together with Crimea, which Moscow grabbed in 2014, make up around 20 percent of Ukraine, including some of its most industrialized territory.
Kyiv has said it will not negotiate with Moscow as long as Putin remains in power.