Ukraine's air force said on Tuesday that it had destroyed 27 of 36 Russian attack drones overnight in the south of the country.

Ukrainian forces downed 27 "Shahed-136/131" drones in the southern Kherson, Mykolaiv and Odesa regions, the air force said on the messaging platform Telegram.

In all, Moscow had launched 36 of the Iranian-made drones from the Crimean peninsula, which Moscow annexed in 2014, it said.

The air force did not say which targets the nine other drones may have struck.

The governor of Mykolaiv, Vitaliy Kim, said on Telegram that one of the drones had been destroyed over his region.

Russia stepped up attacks on ports in southern Ukraine after exiting a deal allowing safe passage for grain shipments through the Black Sea in July.

Kyiv has also warned that Moscow is restarting a campaign of aerial attacks on Ukrainian energy infrastructure, mirroring systematic attacks that last year left millions without heating and water for long periods.

In September, Moscow launched more than 500 Shahed drones -- a monthly record, according to Ukrainian consultancy group Defence Express.