Russia said it thwarted a coordinated Ukrainian attack on Crimea early on Sunday, while drones also targeted Moscow, disrupting air traffic in the capital, and caused a fire at an oil depot in the southwest of the country.
Ukraine in recent days has launched a series of strikes on Russian military targets in occupied Crimea and the Russian Navy Black Sea Fleet's facilities, seeking to undermine Moscow's war efforts in the critical region.
Attacks deep inside Russia, far from the front lines, have also increased, with Moscow's mayor saying at least two drones were shot down in the capital region early on Sunday.
Reuters could not independently verify Sunday's reports and there were no immediate comment from Kyiv.
In an opinion piece late on Saturday, Oleksiy Danilov, the secretary of Ukraine's Security Council, urged Kyiv's allies to speed up the delivery of weapons, saying this was the only way to end the war.
"For example, the complete or partial elimination of the Russian Black Sea Fleet, which is a doable task, should significantly accelerate the process of Russia's search for a way out of the ongoing war," Danilov wrote on the Ukrainska Pravda news site.
Russian air defense systems destroyed at least six drones targeting Crimea from different directions, Russia's defense ministry said on Sunday.
The report on the Telegram messaging app did not say whether there was any damage or casualties in the peninsula, which Russia annexed from Ukraine in a broadly condemned move in 2014, eight years before Moscow's full-fledged invasion.
In the Moscow region, a drone was destroyed over the Istra district and another over the Ramensky district, Moscow Mayor Sergei Sobyanin said on Telegram, adding there were no casualties or damage from drone debris.
At least 30 flights were delayed and six cancelled at Moscow's major airports, Russian state news agencies said - a frequent move by aviation authorities during drone strikes.
In southwestern Russia, a Ukrainian drone damaged an oil depot early on Sunday, sparking a fire at a fuel tank that was later extinguished, the regional governor said.
"There are no casualties, all emergency services are working on the territory of the facility," the governor of the Oryol region, Andrei Klychkov, said on Telegram.
He did not specify whether the depot was hit by debris or targeted by the drone.