On October 23, the Russian Foreign Ministry spokesman, Alexander Lukashevich, said on the ministry’s Twitter account that the Ukrainian government’s use of cluster munitions showed the “barbaric nature of Kiev’s punitive operation,” the Kremlin’s term for the armed conflict in eastern Ukraine. He urged the international community to press Kiev to abandon cluster munitions use.

As evidence he cited a recent Human Rights Watch report that I helped research. We found evidence of cluster munition use in 12 locations. For some of these attacks, in particular several attacks on Donetsk in early October, we gathered significant evidence that Ukrainian armed forces were responsible.

But there are also serious allegations that pro-Russian rebel forces, and possibly Russia itself, have used cluster munitions in eastern Ukraine. All parties to the conflict in Eastern Ukraine have access to the same weapons, so it is not always possible to draw definitive conclusions with respect to specific attacks. In one case we documented in our report, cluster munitions killed 3 civilians and injured 17 in Starobesheve, a village south of Donetsk. The attack took place during  a major offensive by Russian-backed rebels against Ukrainian armed forces, who eventually  abandoned the area with very significant losses.

Ukrainian authorities immediately accused Russian forces of firing cluster munitions from Russian territory. Our on-the-ground investigation established that, given the incoming direction, these cluster munitions could have been fired by either Ukrainian or Russian forces. While circumstances raised the possibility of Russian or pro-Russian rebel responsibility, we ultimately made no definitive attribution of responsibility for this attack. But this case and others warrant more investigation.

Russia has used cluster munitions before. During the Georgia-Russia war over South Ossetia in 2008, Human Rights Watch documented that both Russian and Georgian forces used cluster munitions on several occasions. The Russian government denied using cluster munitions “in the area of the Georgian-Ossetian conflict,” despite conclusive evidence.

Russia’s Foreign Affairs Ministry likes to cite our reports when we criticize the Ukrainian authorities. But as we pointed out the last time, they should also condemn violations by pro-Russian rebels.

The international community should indeed press the Ukrainian authorities to stop using cluster munitions. If the Russian authorities are sincere in their condemnation, they should publicly commit to not use cluster munitions or supply them to the rebels, and should join the international treaty banning their use. Moreover, they should also press pro-Russia rebels not to use these weapons and investigate allegations that they did use them.