At least 50 local residents were evacuated from the village of Primiussky, the spokesman said adding that no one was injured.
The shells came from the combat area in the embattled Donetsk Region where the Ukrainian army is conducting a military operation against local militia. The conflict in eastern Ukraine has turned into a civil war involving tanks, aviation and incendiary bombs.
"During the inspection, the investigators who were wearing clothes with insignia and inscriptions came under intensive mortar fire," he said.
Markin added that the attack on the Russian team was targeted but poor training of Ukrainian servicemen and prompt evacuation of the investigators helped to prevent casualties.
Preliminary reports say that an underage girl was slightly wounded in the accident, he added.