Ukraine's state media has reported that at least 24 people, including 13 children, were killed in a Russian attack on a convoy of civilians in eastern Ukraine.

The state news agency quoted a statement from police in the Kharkiv region on Saturday.

The attack took place near Kupiansk, which Ukrainian forces recently took back in their counteroffensive.

Ukraine's security service says Russian troops fired at six cars and a truck. It released images of charred vehicles riddled with bullet holes.

Ukrainian authorities said on Friday that a separate attack on civilians traveling in cars in the southeastern region of Zaporizhzhia had killed at least 30 people.