Hundreds of Russian drones and dozens of missiles have struck Ukraine's capital, Kyiv, filling the skyline with columns of smoke.The attack, which occurred on Thursday morning, local time, killed at least 27 people, with the toll likely to rise, in what was the deadliest attack on the capital this year.Ninety-one people were injured and about 130 buildings damaged as explosions reverberated across the capital, prompting thousands of residents to rush to bomb shelters and underground metro stations.The head of the city's military administration, Tymur Tkachenko, warned the death toll was likely to rise as rescue teams sift through rubble in search of trapped residents."Rescue crews will work without interruption until all the debris is cleared," he wrote."Unfortunately, more victims may still be found."Rescuers use a crane to carry a body of a person killed amid Russia's attack on Kyiv. (Reuters: Valentyn Ogirenko)He said teams at one site in an eastern suburb had recovered five bodies while eight residents remained unaccounted.Russia launched 74 missiles and 496 drones during the attack, which Kyiv's Mayor Vitali Klitschko described as the "enemy's most massive attack on the capital".Red Cross warehouse destroyedThe Ukrainian branch of the Red Cross said its key warehouse had been destroyed and about $UAH79 million ($2.5 million) worth of humanitarian aid lost.The site housed humanitarian supplies essential for emergency response operations, supporting healthcare facilities, and delivering life-saving assistance.The Ukrainian Red Cross humanitarian warehouse was destroyed. (Supplied: The Ukrainian Red Cross)"The destroyed supplies included critical equipment such as generators, heat pumps and medical equipment, including stretchers, defibrillators, ultrasound machines and vital signs monitors," The Ukrainian Red Cross said in a press release.The attack also damaged a cargo vehicle used to transport aid."The destruction of the warehouse has caused not only substantial material losses, but has also dealt a serious blow to the humanitarian infrastructure on which the timely delivery of assistance to thousands of people affected by the war depends," The Ukrainian Red Cross said.The destroyed supplies included critical equipment for people in the immediate aftermath of emergencies. (Supplied: The Ukrainian Red Cross)Katarina Mathernova, the EU ambassador to Ukraine, said Russia struck accommodation used by diplomatic personnel."Russia unleashed hell on Kyiv today," she wrote on social media."Seemed like large parts of the city were on fire."Ms Mathernova, who spent the night in a bomb shelter, said the diplomats were unharmed, but their belongings were damaged in a fire. Zelenskyy blames alliesUkrainian President Volodymyr Zelenskyy, who cut short his visit to Ireland to rush home, blamed the destruction in part on a failure of allies to deliver promised air defences.Volodymyr Zelenskiy speaks to the media as he visits the site of a damaged apartment building. (Reuters: Valentyn Ogirenko)"If our partners had delivered on their promises in a timely manner, I think we could have saved more homes and lives today," Mr Zelenskyy said."All we ask of our partners is simply to do what we've agreed on. We're not even asking for more."Yuri Ihnat, a Ukrainian air force spokesperson, said the number of missiles from Russia was unusually high, while the interception rate from Ukraine was low, as the country grappled with shortages of Patriot missiles in recent months.Residents stand near a damaged apartment building. (Reuters: Viacheslav Ratynskyi)Later, in his nightly video address, Mr Zelenskyy said the issue of air defences would be "one of the key outcomes" of next week's NATO summit in Turkey."If, of course, NATO still means anything to the allies," he said."Europe must have its own sufficient capability to defend against all types of threats, including this one — from Russian ballistic missiles."Casualties reach '2 million' since invasionRussia's invasion of Ukraine has caused more than 2 million military casualties, with Moscow's forces bearing the brunt of the losses, according to a US think tank.The Center for Strategic and International Studies (CSIS) said "combined Russian and Ukrainian casualties have exceeded 2 million", in its report published on Wednesday, the day before the latest deadly attack.According to the CSIS, the Russian military has suffered 1.4 million battlefield casualties (killed, wounded and missing) and as many as 450,000 deaths since February 2022.Ukrainian forces have meanwhile suffered between 525,000 and 625,000 casualties and between 125,000 and 150,000 fatalities during the same period."These rates are astounding," the CSIS said."Russian fatalities in Ukraine are more than four times greater than all US fatalities in all wars combined since World War II, and more than nine times greater than all Soviet and Russian fatalities in all wars combined since World War II."