Russia’s Defense Ministry has found poisonous chlorine and white phosphorus in nine samples from southwestern Aleppo, the ministry’s spokesman Maj. Gen. Igor Konashenkov said Monday.

“Experts from the Russian Defense Ministry conducted an express test of nine samples of shell fragments and earth from shell craters that were taken in District 1070 in the southwestern Aleppo suburb. They confirmed that chlorine and white phosphorus were used to fill munitions,” he told reporters.

The spokesman said scientists from the Russian Armed Forces’ Radiological, Chemical and Biological Defense Troops were gathering evidence that militants in the northern Syrian city were using shells that contained poisonous substances against civilians and Syrian armed forces.

Maj. Gen. Konashenkov added the UN-backed Organization for the Prohibition of Chemical Weapons (OPCW) was reluctant to join forces with Russia or send experts to Aleppo, “which does not stop some OPCW members from apportioning blame from afar and ignoring the evidence that chemical weapons are being used against civilians,” he added.