Russian forces have captured two villages in eastern Ukraine and are now pressing to encircle Ukrainian soldiers at two locations along the frontline, according to an analysis of the battlefield on Monday.

The two villages, Nevelske and Vodiane, were captured by Russian troops on Sunday, according to DeepState, a group of analysts mapping the battlefield. DeepState’s analysis is based on sources in the Ukrainian military and open-source data like satellite imagery and photos and video posted on social media.

Russian forces have been expanding the territory they control around a key objective in the region, the strategic city of Pokrovsk, which has been strengthened in recent days by Ukrainian reinforcements, the analysis shows.

Now, Russia appears to be trying to cut off Ukrainian forces with pincer movements in two areas — to the south of Pokrovsk and in a pocket of Ukrainian-held territory near the town of Vuhledar, another strategically important site.

Control of those areas would allow Russian forces to broaden their lines of approach toward Pokrovsk, a logistics and transit hub that has been a focal point of the war in recent months, experts say.

“They are trying to strengthen their flanks in this way” along the main axis of attack toward Pokrovsk, said Mykhailo Samus, deputy director at the Center for Army, Conversion and Disarmament Studies in Ukraine, an independent institution. “Their route to Pokrovsk depends on those flanks.”