Rescue efforts at a major Kyiv children’s hospital, hit by a Russian missile, continued into a second day on Tuesday, Ukrainian President Volodymyr Zelenskyy said, as officials reported a nationwide casualty toll of 42 dead and nearly 200 injured from the previous day’s intense barrage that struck multiple cities.

Zelenskyy said on the social media platform X that 64 people were hospitalized in the capital, along with 28 in Kryvyi Rih and six in Dnipro, both cities in central Ukraine.

This marked Russia’s heaviest bombardment of Kyiv in nearly four months and one of the deadliest incidents of the war, targeting seven of the city’s 10 districts. The attack on the Okhmatdyt children’s hospital, interrupting open-heart surgery and forcing young cancer patients to seek treatment outdoors, sparked international outrage.

The 10-story hospital, Ukraine’s largest medical facility for children, was treating around 670 patients at the time of the attack, according to Okhmatdyt’s Director General, Volodymyr Zhovnir, on Tuesday. The missile struck a two-story wing of the hospital.

“The building where we conducted dialysis for children with kidney failure or acute intoxication is entirely ruined,” he told reporters, estimating the overall damage to the hospital at $2.5 million.

Danielle Bell, the head of a U.N. team monitoring human rights violations in Ukraine, stated that at least two people were killed at the hospital and approximately 50 were injured, including seven children.

She added that the casualty count could have been far higher if patients hadn’t been moved to a bunker when air raid sirens first sounded.

Authorities were working to restore the hospital’s power and water supply, Zhovnir said.

Kyiv city officials declared Tuesday an official day of mourning. Entertainment events were prohibited, and flags were lowered in the capital.

Russia denied responsibility for the hospital strike, maintaining its stance that it does not target civilian infrastructure despite substantial evidence to the contrary, including reporting by the Associated Press.

Kremlin spokesperson Dmitry Peskov reiterated this position on Tuesday, citing a Russian Defense Ministry statement blaming a Ukrainian air defense missile for partially destroying the hospital.

Bell, the head of the U.N. team, dismissed this argument. She said an assessment of video footage and on-site findings indicated that the hospital “took a direct hit, rather than receiving damage due to an intercepted weapons system.”

The hospital was likely struck by a Russian Kh-101 cruise missile, Bell said, a claim echoed by Ukrainian officials.

Officials reported that the bodies of three more individuals were found Tuesday beneath the rubble of a residential building in Kyiv’s Shevchenkivskyi district, raising the death toll in that specific building to 10.

The Russian assault on Monday came on the eve of a NATO summit in Washington where alliance nations are expected to pledge new aid for Ukraine.

Meanwhile, Russian President Vladimir Putin was hosting India’s Prime Minister Narendra Modi in Moscow.

New Delhi’s significance as a key trading partner has increased since the Kremlin launched its military operation in Ukraine in February 2022.

Zelenskyy expressed sharp criticism of Modi’s visit, stating on X late Monday: “It is a huge disappointment and a devastating blow to peace efforts to see the leader of the world’s largest democracy hug the world’s most bloody criminal in Moscow on such a day.”

Meanwhile, Russian military and regional officials said Tuesday that Ukrainian drones targeted six Russian regions overnight, in what appeared to be a larger-than-usual aerial attack by Kyiv’s forces.

Russia’s Defense Ministry stated that air defense systems in five Russian southern and western regions “destroyed and intercepted” a total of 38 Ukrainian drones.