A convoy of civilian vehicles trying to escape fighting near the city of Kharkiv was fired upon, killing several people, the Kharkiv region police said. Others are missing.
Serhiy Bolvinov, chief of the investigation department, said police had lost contact with the convoy a few days ago.
There were 15 cars traveling near the village of Staryi Saltiv, which has seen heavy fighting in recent days as Ukrainian forces launch a counter-attack against the Russians east of Kharkiv.
At the time, the convoy was trying to reach territory controlled by the Ukrainians, Bolvinov said.
"Due to the ongoing combat, it was not possible to reach the place of the column," Bolvinov said.
The wreckage of the convoy was found on Friday, he said. Having arrived at the scene, investigators found a broken enemy tank and the bodies of two Russian soldiers.
A further 300 meters away, six cars with bullet holes were found. Four corpses were found in the cars and, according to Bolvinov, they appeared to be some of the civilians who had been in the convoy.
The remains of a 13-year old girl had been positively identified, he said.
Bolvinov gave no details about what may have happened to other vehicles in the convoy.