Today the OSCE have posted images of Russian MLRS rocket systems & artillery. The July 30th image shows a large compound near the town of Krustalnyi (Krasnyi Luch). This has been used by Russia’s forces from 2016. Close to the Ukrainian/Russian border, there’s also a large Russian military base nearby, with a permanent combat battle group of around 200 tanks, artillery and armoured fighting vehicles based there ( see last 2 pics).
The second Aug 1st OSCE image (4th pic) shows Russian Self propelled artillery on front line. The location is near the Ukrainian held area around Krymske. This region suffers regular shelling and firing attacks by Russian forces. As the image shows, to avoid detection, Russia moves much of its artillery around at night. In this case it didn’t work.
Both locations are in Ukraine’s Luhansk Oblast (province).