KYIV, Ukraine >> A week after Russia captured Vuhledar, a town that anchored Ukraine’s defenses in the country’s southeast, Moscow’s forces are continuing to advance in the area, pushing into or flanking several towns as they try to break through Ukrainian lines.

Russian troops have now entered Toretsk, a city about 50 miles north of Vuhledar, and are advancing toward its center, according to battlefield maps compiled by independent groups analyzing combat footage. A Ukrainian army spokesperson, Anastasia Bobovnikova, said late Monday that Russia had entered the city, noting that “fighting is taking place literally at every entrance” to it.

The Russian army has also made small advances along the jagged, curving front line that stretches from Toretsk to Vuhledar in eastern Ukraine’s Donetsk region, closing in on several strategic towns and cities, the battlefield maps show.

The fierce fighting in the area reflects the Kremlin’s long-standing goal of capturing all of the Donetsk region, which it already partly controls. “This is clearly what the Russians are aiming at,” said Franz-Stefan Gady, a Vienna-based military analyst. “As a result, this is where the heaviest fighting is happening.”

In the west

The flurry of activity in eastern Ukraine contrasts with the situation in the Kursk region in western Russia, which Ukrainian forces partly invaded in August. Ukraine’s troops made swift gains early in the offensive, some of which were reversed by Russian counterattacks last month. The front line has recently stabilized, with each side making only marginal advances.

The front line near Kharkiv, a major city in Ukraine’s east toward which the Russians pushed this spring, has similarly remains unchanged. But the city of Kharkiv itself is regularly battered by Russian strikes. Russian attacks Tuesday killed at least two civilians, according to local officials.

Russian momentum

Russia remains far from capturing the entire Donetsk region. As of now, it controls about two-thirds of the area. To seize the remaining third, it would need to break through several Ukrainian defensive lines of trenches and anti-tank ditches, and battle its way through densely populated urban centers — a grueling fight that U.S. officials believe the Russian army cannot successfully wage in the short term.

Still, the slow but steady advance of Russian troops in the Donetsk region since the beginning of the year has enabled the Kremlin to capture or threaten several Ukrainian bastions that hold the keys to Ukraine’s defense of the area, because they are densely fortified and located on advantageous terrain like high ground. These gains have positioned Moscow favorably, giving it the potential to fully seize the region in the future, military analysts say.