More than a 100 days after Russia began its invasion of Ukraine, it is the strategic eastern city of Sievierodonetsk that remains the focus of intense fighting in the battle's current phase. On Monday, the regional governor of the area said that the city was witnessing the “fiercest fighting”, with the situation “worsening a little” for Ukraine. Location Located nearly 140 km south of the Russian border, Sievierodonetsk is one of the largest cities of the Donbas region. It is located near the left bank of the Siverskyi Donets river, and has a population of over a lakh. Administratively, Sievierodonetsk falls under Ukraine's Luhansk oblast (province). It is a big industrial hub known for chemical works and machine-building factories. Strategic importance The offensive is part of a plan that Russian president Vladimir Putin has articulated as "complete liberation" of Donbas. When Russia talks about 'liberating' Donbas, it broadly refers to controlling Ukraine's eastern regions of Donetsk and Luhansk. If the city of Sievierodonetsk falls, then it will allow Russia to control the entire Luhansk region. Ukrainian military analyst Oleh Zhdanov told The Associated Press that Russia wants to quickly capture the region before arms from the West arrive and make the region's complete dominance nearly impossible. During the war in Donbas in May 2014, Sievierodonetsk was briefly captured by Russian forces, but Ukraine regained control of the city two months later. In the current offensive, Russia shifted its focus on Sievierodonetsk after failing to seize Ukraine’s capital, Kyiv, in the first phase of the war. Current situation The governor of Luhansk province in a Telegram update blamed Russian forces of trying to level Sievierodonetsk to the ground, adding that the shelling has “increased tenfold”. Many fear that the city could become the next Mariupol, the southern port city that was heavily destroyed before it fell into Russian hands. In its daily intelligence update, the UK's Ministry of Defence said that heavy fighting is continuing around the contested areas of Sievierodonetsk. The governor on Monday claimed that Ukrainian forces had “liberated almost half of the city. But now the situation has worsened a little for us again”. Newsletter | Click to get the day's best explainers in your inbox