A Ukrainian strike in Crimea resulted in at least three deaths, following Ukrainian attacks on energy and military sites in Saint Petersburg. US officials expressed concern about potential escalation.

A Ukrainian strike killed at least three people in Crimea, Moscow-installed authorities said on Thursday, a day after Kyiv targeted energy and military facilities in Saint Petersburg during Russia's flagship economic forum. US Secretary of State Marco Rubio warned of a "real" risk of escalation, while Ukraine described the attacks as justified retaliation for intensified Russian strikes on its territory.