Belgorod, a Russian city which lies just north of the Ukrainian border not far from Kharkiv, has reportedly come under repeat fire from Ukraine forces in the last 24 hours. "The governor of a Russian border region accused Ukraine of shelling an apartment block there on Thursday but a Kyiv official said a stray Russian missile was to blame, in only one of a series of apparent strikes on Russian border towns," Reuters reported Thursday, citing that "a school had been damaged in a village close to the border, and that the top floor of an apartment block had been struck in the city of Belgorod."

While this is not the first instance of Ukrainian cross-border strikes (Kiev's denial of responsibility notwithstanding), on Friday things have escalated with a reported nighttime missile strike on Belgorod's thermal power plant, with further reports that it has plunged much of the city into darkness.

If this is indeed the result of a confirmed Ukrainian missile strike, it will mark a massive escalation amid the past week of multiple serious escalations, including the Kerch Strait bridge attack, given it's a major hit on Russian soil.

Does this marks the start of the Ukrainian side hitting back at Russia's energy infrastructure? Early in the week President Vladimir Putin announced the start of aggressive targeting of Ukraine's energy grid. 

An additional question remains: are Ukraine forces utilizing longer-range missiles transferred from Western allies? If so, this could trigger a huge response from Moscow, despite Putin in an earlier Friday speech signaling he isn't planning further large-scale airstrikes across Ukraine for the time being.

A reported missile strike and moment of impact against the power plant: