A Ukrainian strike killed at least three people in Crimea, the region's Moscow-installed authorities said on June 3, a day after Kiev targeted energy and military sites in Saint Petersburg where Russia was hosting an economic forum.

The incident comes a day after Russia launched a massive drone and missile barrage at Ukraine, killing at least 23 people. #EuropeNews

Ukrainian drones attacked energy and military sites in St. Petersburg as Russia's major economic forum was set to kick off in the city, a day after Moscow killed 23 people across…