Russia's Defense Ministry on Sunday said that Ukraine had launched drone strikes targeting airfields across five regions.

"In the Murmansk and Irkutsk regions, the launch of FPV drones from an area in close proximity to airfields resulted in several aircraft catching fire," the ministry said.

Russia said most of the attacks were repelled.

Ukraine's SBU intelligence agency said it was behind the attacks on Russian planes, saying they caused $7 billion (€6.17 billion) in damage.

"This is the estimated cost of the enemy's strategic aviation, which was hit today as a result of the SBU's special operation," they said in an online post.

Strategic bombers reportedly destroyed

Previously, the AP news agency cited a Ukrainian security official as saying the SBU attack destroyed more than 40 Russian planes using drones deep inside Russian territory.

The reportedly struck various planes including Tu-95 and Tu-22M strategic bombers and surveillance-focused A-50, the official said on condition of anonymity.

The attack comes on the same Day Ukraine's President Volodymyr Zelenskyy said a delegation would travel to Istanbul for a fresh round of peace negotiations with Russia on Monday.

Sunday also saw Ukraine's military report waves of Russian drone and missile attacks overnight.

Ukraine's army said Russia's "missile strike on the location of one of the training units" had killed a dozen soldiers, most of whom had been in shelters during the attack.

Edited by: Darko Janjevic