Russia reported that it had shot down a drone heading for Moscow in the third such attack in a week, while officials on both sides said on Sunday that Ukraine had struck two bridges linking Crimea to the mainland.
Both countries have stepped up attacks on each other's troops, weaponry and infrastructure supporting the war as Ukraine seeks to dislodge Russian forces who have dug in across southern and eastern Ukraine since their invasion last year.
The Moscow-appointed head of Crimea said the Chonhar bridge to the peninsula, which was annexed from Ukraine by Moscow in 2014, had been damaged by a missile strike.Â
Another of the three road links between Crimea and Russian-occupied parts of mainland Ukraine, near the town of Henichesk, was shelled and a civilian driver wounded, a Moscow-appointed official said.
Traffic was halted on a third bridge, linking Russia to Crimea, after both sides said a Ukrainian naval drone full of explosives struck a Russian fuel tanker vessel overnight from Friday to Saturday, the second such attack in 24 hours.
In a video address on Sunday, Zelenskiy said advanced air defence systems, including the US-built Patriot and Germany's IRIS-T, were proving "highly effective" and had "already yielded significant results".
Zelenskiy said Ukraine had shot down "a significant part" of Russia's attacks over the past week, including 65 missiles of various kinds, and 178 assault drones, including 87 Shaheds.
In Russia, Moscow's Vnukovo airport suspended flights on Sunday, citing unspecified reasons outside its control. Moscow mayor Sergei Sobyanin said a drone had been shot down south of the capital.
At least 10 Russian missiles appear to have got through Ukraine's air defences in the overnight attack, which Ukraine's air force said involved 70 air assault weapons including cruise and hypersonic missiles as well as Iranian-made drones.
The attacks followed what Zelenskiy said was a bomb attack on a blood transfusion centre in the town of Kupiansk, around 16 km from the front in the eastern Kharkiv region.
"There are dead and wounded," he said on his Telegram channel, describing the strike as a "war crime".
Reuters could not immediately verify the report.
Russia denies deliberately targeting civilians or military hospitals in its full-scale invasion of Ukraine, which has killed thousands of people, uprooted millions and destroyed cities.
Ukraine is two months into a gruelling counteroffensive to try to push out Russian forces occupying almost a fifth of its territory.