isnt it obviously to starve them? He has realised he doesn’t need to lose a load of Russian soldiers fighting in the factory, he has just blocked them in so nothing can get in or out. Either 2,000 odd soldiers plus civilians are going to starve or dehydrate to death very soon or they will need to exit the plant and surrender. First very smart move by putin in 2 months.
I wonder if that will come back to haunt them? All civilians in there leave and have the injured troops 'surrender'. Assuming they have stockpiles to last the Ukrainians in there can hunker down while the city slowly goes 'back to normal'. The Russians will eventually have to leave the minimum numbers guarding it and the city itself as they can afford so they can spare the rest to move on. But it's a huge sprawling area surrounded by water. I bet supplies will get smuggled in eventually. That will allow them to cause all manner of headaches running an insurgency by being able to pop up all over the city and then disappear again into what's essentially a fortress island.
Or the supply situation is a lot worse than that and the vast majority are forced to surrender soon.