KYIV, Ukraine — Ukrainian air defenses downed 32 of 35 Shahed exploding drones Russia launched early Tuesday, most of them in the Kyiv region, officials said, in a bombardment that exposed gaps in the country’s air protection after almost 16 months of war.

Russian forces mostly targeted the region around the Ukrainian capital in a nighttime drone attack lasting around three hours, officials said, with Ukrainian air defenses shooting down about two dozen.

The attack was part of a wider bombardment of Ukrainian regions that extended as far as the Lviv region in the west of the country, near Poland.

The Shahed drones made it all the way to Lviv because of the inability of air defense assets to cover such a broad area, Ukrainian air force spokesman Yuriy Ihnat said.

Air defense systems are mostly dedicated to protecting major cities, key infrastructure facilities, including nuclear power plants, and the front line, he said.

“There is a general lack of air defense assets to cover a country like Ukraine,” Lviv Gov. Maksym Kozytskyi said.

Russia also struck the southern Zaporizhzhia region with ballistic missiles.

Ukraine’s air defenses have been reinforced with sophisticated weapons from its Western allies, increasing the success rate at knocking down incoming drones and missiles.

A winter bombardment by Russia damaged Ukraine’s power supply, though speedy repairs blunted that Kremlin effort.

The latest aerial assaults coincided with the early stages of a Ukrainian counteroffensive aiming to dislodge Kremlin forces from territory they’ve occupied since a full-scale invasion in February 2022.

The counteroffensive is up against heavily mined terrain and reinforced defensive fortifications, according to Valerii Zaluzhnyi, commander-in-chief of Ukraine’s armed forces.

Russia has also mustered a large number of reserves, Zaluzhnyi said in a post accompanying a video of him visiting front-line positions with other officers.

Heavy battles are taking place in eastern Ukraine, around Bakhmut, Lyman, Avdiivka and Marinka, the Ukrainian armed forces said. Russia shelled 15 cities and villages in the eastern Donetsk region, wounding five civilians, according to Ukraine’s presidential office.

Russia has relocated about 20,000 troops from areas in the Kherson region after flooding from the recent Kakhovka Dam collapse made it impossible for Ukraine to conduct an offensive there, Ukrainian military analyst Roman Svitan said.

The flooding removed the need for the Kremlin’s forces to protect about 180 miles of the more than 600-mile front line, according to Svitan, and allowed Moscow to concentrate troops in the Zaporizhzhia and Donetsk regions where intense fighting is occurring.

Svitan said the Zaporizhzhia region appears to be the focus of the Ukrainian counteroffensive, seeking to smash through Russia’s land corridor with the Crimean Peninsula.