Where in Ukraine Russia amasses quarter of its entire military grouping?

Russia has deployed at least 100,000 servicemen in Lyman-Kupyansk sector. Volodymyr Fitio, spokesman for the AFU Land Forces, said this, Defense Express reports. 

He observes that the Russian army has yet to achieve strategic success in this area; Russian forces initiated active assaults in this area a few days after the start of their offensive in the Avdiivka sector. Russia aims to retake Kupyansk, which is a vital supply hub.

"Over the past day, Russian forces launched 613 attacks, 9 airstrikes and a total of 17 combat engagements in this area. At the same time, the Ukrainian Defense Forces killed 194 invaders in the Lyman-Kupyansk sector over the last day, but the enemy is restoring the destroyed units by pulling up reserves," Defense Express writes. 

Thus, Russia has concentrated a quarter of all its forces in Ukraine in this area. Earlier, Andriy Yusov, a representative of the Main Intelligence Directorate, stated that Russia has deployed over 400,000 troops in Ukraine.

Concerning the situation in the Avdiivka sector, where Russian soldiers intensified their onslaught on October 10, the invading forces continue to strive to advance in this area despite heavy casualties in both manpower and equipment.

At the same time, the city is being shelled on a daily basis. As the local military administration head, Vitaliy Barabash, has stated, such heavy shelling will entirely demolish the city in 2–3 weeks.