Ukrainian authorities have announced Russian drone attacks on southern Ukraine's Odesa region have injured at least four people.

Odesa regional authorities on Monday posted on social media that Russian forces launched fresh drone attacks against the region, and also destroyed a grain depot.

Ukrainian police say Russia's major attack on Odesa over Sunday killed one civilian, injured more than 20 others and damaged an Orthodox cathedral in the city's historic center which is on the World Heritage List.

Meanwhile, Russia's defense ministry on Monday announced that Moscow came under attack by two drones, but the attack was thwarted when the drones were downed. It says there were no casualties.

Russian media have reported one drone hit a high-rise office building in southern Moscow, while drone fragments have been found in the southwestern part of the capital.

The ministry also says Ukrainian forces launched a drone attack consisting of 17 drones in Crimea, but they were either shot down or suppressed. Russia unilaterally annexed the region in 2014.

The ministry maintains that Ukraine was behind both attacks.