Russia targeted Ukraine with drones in another massive attack early Thursday as President Volodymyr Zelenskyy traveled to Spain to rally support from Western allies at a summit of some 50 European leaders.

Ukraine's air force said the country's air defenses intercepted 24 out of 29 Iranian-made drones that Russia launched at the southern Odesa, Mykolaiv and Kirovohrad regions.

Andriy Raykovych, the head of the Kirovohrad regional administration, said that an infrastructure facility in the region was struck and emergency services were deployed to put out a fire. He said there were no casualties.

The attack came as Zelenskyy arrived in Granada in southern Spain to attend a summit of the European Political Community, which was formed in the wake of Russia's February 2022 invasion of Ukraine.

"The key for us, especially before winter, is to strengthen air defense, and there is already a basis for new agreements with partners," he said in a statement posted on his Telegram channel.

Last winter, Russia targeted Ukraine's energy system and other vital infrastructure in a steady barrage of missile and drone attacks, triggering continuous power outages across the country. Ukraine's power system has shown a high degree of resilience and flexibility, helping alleviate the damage, but there have been concerns that Russia will again ramp up its strikes on power facilities as winter draws nearer.

Zelenskyy noted the Granada summit will also focus on "joint work for global food security and protection of freedom of navigation" in the Black Sea, where the Russian military has targeted Ukrainian ports after Moscow's withdrawal from a United Nations-sponsored grain deal designed to ensure safe grain exports from the invaded country's ports.

The U.K. Foreign office cited intelligence suggesting that Russia may lay sea mines in the approach to Ukrainian ports to target civilian shipping and blame it on Ukraine. "Russia almost certainly wants to avoid openly sinking civilian ships, instead falsely laying blame on Ukraine for any attacks against civilian vessels in the Black Sea," it said, adding that the U.K. was working with Ukraine to help improve the safety of shipping.

In other Russian attacks on Ukraine in the past day, two civilians were killed in the shelling of Kherson and another one died after a Russian strike on the city of Krasnohorivka in the eastern Donetsk region. At least eight people were wounded by the Russian shelling, according to Ukraine's presidential office.

Ukraine, in its turn, has struck back at Russia with regular drone attacks across the border.

Roman Starovoit, the governor of Russia's Kursk region that borders Ukraine, said Ukrainian drones attacked infrastructure facilities in several areas, resulting in power cuts.

Starovoit also said Ukrainian forces fired artillery at the border town of Rylsk, injuring a local resident and damaging several houses.