Attacks by Ukrainian long-range drones caused flight disruption at Moscow’s main airports for a third straight day on Wednesday as Russia prepared to receive the Chinese president and other foreign leaders for the annual Victory Day military parade in Red Square.Russian flag carrier Aeroflot cancelled more than 100 flights to and from Moscow. More than 140 flights were delayed as Russian planes were repeatedly grounded, flight data showed, because of what officials described as the Ukrainian drone threat and amid heightened security measures around the Victory Day events. Russian air defences repelled an attack by nine drones close to the Russian capital, Moscow mayor Sergei Sobyanin said.Earlier on Wednesday, the Russian defence ministry said its forces had downed 524 drones over the past 24 hours. The ministry did not specify the locations where the drones were destroyed.Though Ukrainian drones have targeted Moscow in the past, the sustained attacks appeared designed to disrupt preparations for the 80th anniversary celebrations marking victory over Nazi Germany in WWII — Russia’s biggest secular holiday of the year.The repeated assaults could unnerve Russians, who have been told by President Vladimir Putin that the more than three-year war with Ukraine is going well, as well as potentially embarrass him in front of his illustrious guests.Security is expected to be tight for Friday’s centerpiece parade. Foreign dignitaries, including China’s President Xi Jinping and Brazilian President Luiz Inacio Lula da Silva, arrived on Wednesday.Russia plans a unilateral 72-hour ceasefire to coincide with the celebrations in Moscow. In March, the US proposed a 30-day truce in the war, which Ukraine accepted, but the Kremlin has held out for ceasefire terms more to its liking.Ukrainian President Zelenskyy said last weekend that his country cannot provide security assurances to foreign officials planning to visit the Moscow events. Russia could stage provocations and later attempt to blame Ukraine, he said. “Our position is very simple: we cannot take responsibility for what happens on the territory of the Russian Federation,” he said. “They are the ones providing your security, and we will not be offering any guarantees.” Zelenskyy said that he had instructed Ukraine’s foreign ministry to advise foreign delegations against visiting Russia.