Donetsk is on the front line and has been since the beginning. The city center seems to be less than 10km from the Ukrainian trenches. Therefore the Russian lines (or DPR in that area I suppose) support elements must be right in Donetsk. Mortar and artillery positions, supply dumps, vehicle parks, etc.
The target is the city
The civilian infrastructure
The bombs ( cluster bombs) and shells are from Ukraine
Which the ukes have been doing since 2014
Please keep up with the news
The news is covering the 24/7 bombardment
However…laughably…blaming it on Russia
So you would have to believe that the Russians are bombing their own troops and DPR allies