Russian drone strikes damaged five buildings in the capital, Kyiv, on Wednesday even as Ukrainian air defenses thwarted many more, authorities said. No casualties were reported.

The attacks underline how Ukraine's biggest city remains vulnerable to the regular Russian attacks that have devastated infrastructure and other population centers, mostly in the country's east and south in recent weeks.

Ukrainian President Volodymyr Zelenskyy, in a brief video statement, said the “terrorists” fired 13 Iranian-made drones, and all were intercepted. Such drones have been part of Russia’s firepower along with mortar, artillery and rocket strikes across Ukraine in recent weeks.

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The head of the Kyiv city administration, Serhii Popko, wrote on Telegram that the strikes came in two waves, and shrapnel from the intercepted drones damaged one administrative building, while four residential buildings sustained minor damage.

The capital remained largely calm after the attack, which occurred around daybreak and before the start of the business day, and the destruction appeared limited compared to fallout from other Russian strikes that have taken lives and upended livelihoods across the country in recent weeks.

As the workday began in Kyiv, authorities sounded the all-clear on an air raid alert system.

The strike left a gaping hole in the roof of a three-story administrative building in the central Shevchenkyvskyi district, and the blast blew out windows in parked cars and in a neighboring building. It was not immediately clear whether there were any casualties.

In a sign of Ukrainians' reactivity and resilience to hundreds of such strikes in recent months, clean-up crews were on site quickly to shovel away the rubble and roll out plastic sheeting to cover blown-out windows to cope with freezing temperatures in the snow-covered capital. One man, unfazed, pushed his son on a swing set on a nearby playground as the crews did their work.

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The attack underscored the continued vulnerability of the capital, which has largely been spared of damage in the latest phases of Russia's nearly 10-month onslaught in Ukraine.

Ukraine in recent weeks has faced a barrage of Russian air strikes across the country, largely targeting infrastructure, as well as continued fighting along the front lines in the eastern and southern regions.

During the latest round of Russian military volleys on Dec. 5, more than 60 of 70 strikes were intercepted by air defense systems, including nine out of 10 targeting the capital and its region, Ukrainian officials have said.

U.S. officials said Tuesday the United States was poised to approve sending a Patriot missile battery to Ukraine, agreeing to an urgent request from Ukrainian leaders desperate for more robust weapons to shoot down incoming Russian missiles.

Zelenskyy pressed Western leaders as recently as Monday to provide more advanced weapons to help his country in its war with Russia. The Patriot would be the most advanced surface-to-air missile system the West has provided to Ukraine to help repel Russian aerial attacks in the war between the countries that erupted with Russia’s invasion of Ukraine on Feb. 24.

U.S. officials also said last week that Moscow has been looking to Iran to resupply the Russian military with drones and surface-to-surface missiles.