Both Ukrainian and Russian forces are claiming hits on Vuhledar, in the Donetsk region, as intense battles for control of the strategic town in eastern Ukraine continued on Monday.

The General Staff of the Armed Forces of Ukraine said Monday Ukrainian units defending the contact line near Vuhledar have “recently ‘welcomed’ the occupiers and turned their temporary stay on our land into a living hell” by inflicting heavy losses.

CNN has not been able to independently verify those claims.

The Russian Ministry of Defense said Monday Russian forces had made progress in the area.

“Units of the ‘Eastern’ group of forces, continuing their successful offensive, took more advantageous positions and inflicted fire on units of the 1st Tank Brigade of the Armed Forces of Ukraine near the settlement of Vuhledar in the Donetsk People’s Republic,” said the ministry.

Earlier Monday, the leader of the self-declared Donetsk People’s Republic (DPR) told Russian state media that Russian forces had established a presence in the eastern part of Vuhledar.

In his nightly address Sunday, Ukrainian President Volodymyr Zelensky said the situation in the area is “very tough” as “Bakhmut, Vuhledar and other areas in the Donetsk region are under constant Russian attacks.”

“There are constant attempts to break through our defense. The enemy does not count its people and, despite numerous casualties, maintains a high intensity of attacks,” Zelensky said.

Vuhledar is a major logistics hub and its seizure would help cut off the Ukrainian army’s supplies, and enable Russian and separatist forces to launch strikes on the Ukrainian military in several directions, according to DPR separatist officials.