Ukrainian attacks on Russian regions on and near the border with Ukraine have killed 652 civilians so far, the head of Russia's Investigative Committee told the TASS news agency in remarks published on Sunday, without providing evidence.

Twenty-three children were among those killed, Alexander Bastrykin, the head of the committee, told TASS.

Nearly 3,000 have been wounded, he added.

Both sides deny targeting civilians in their attacks in the war that Russia launched with its full-scale military action against Ukraine three years ago. But thousands of civilians have been killed in the conflict, the vast majority of them Ukrainian.