Is that what Russia claims when it does so? My recollection is that usually Russia offers no explanation or they deny their responsibility; they'll say like, oh we were struck some military targets, but that apartment building was hit by Ukraine's own missile defense system. Another difference is that Ukraine doesn't have any sort of interconnected tunnel warfare system, let alone one that runs underneath every major city; it would be incredible to say that there were military tunnels under all these apartment buildings. Further, you can see from the Russian attacks that the missiles are frequently launched twenty or thirty at a time, and many of them don't hit anything at all. Seems like it's actually indiscriminate, intentional targeting of civilians: chiefly, I'm not aware of a single attempt by Russia to warn civilians before an airstrike, have seen zero screenshots and heard zero audio recordings of warnings. Ukraine is also credible when it says "there was no military target," unlike Hamas, which incredibly denies everything. Again, if you throw a dart at a map of Gaza, you're pretty much going to hit a tunnel: 400 miles of tunnels with 5,000 shafts in an area that is 25 miles wide at its widest point.
Russia doesn't usually explain or elaborate that much. They just say "we only target military targets, whether obvious or disguised" and then shoot a missile at an school or something, killing civilians. And they could be telling the truth, because Ukraine has used civilian infrastructure like that before, but Russia never provides evidence that the specific school was used that way. This is pretty much the Russia/Ukraine equivalent of the tunnel system, bc you have valid military targets around/in some civilian infrastructure, but Russia ends up just bombing everything.
You also mentioned russian attacks being "actually indiscriminate", but half of the bombs that Israel has dropped on Gaza have been unguided, so that seems like it's also indiscriminate.
There is no Russia/Ukraine equivalent of the tunnels. The Hamas tunnels are unprecedented in world history. Russia and Ukraine are both legitimate countries with legitimate governments.
Amnesty has no credibility anymore unfortunately. It is Hamas that has a duty of distinction, but it doesn't usually wear uniforms and hides its fighters, weapons, and infrastructure right under people's homes, hospitals, and school. Ya know, because it's an illegal terrorist organization and in no way a legitimate government/state? Has Hamas ever once prosecuted its own people for war crimes? No, but it does stone people to death for being "collaborators." Why don't you stop trying to run defense for literal terrorists, designated as such by a few dozen different countires?
It's funny how Amnestly always loses all credibility when it's reporting on a genocide. Same as all the other organizations you don't think are credible anymore... Funny how when Israel reports things, they aren't "just reports" but ground truths, except for the ones that were so undeniable so you had to do a tongue-in-cheek admission... and when the Palestinians and their human rights organization report on it, it's just a "report"....