MOSCOW — The Russian military and a main Syrian opposition group traded allegations Friday about whether new evidence indicates that either rebels or Syrian military used chemical weapons in the area of Aleppo where government forces are trying to regain control of areas they recently lost to insurgents.

Russian Defense Ministry spokesman Major General Igor Konashenkov said that ministry experts have found unexploded ordnance and fragments of munitions containing chlorine and white phosphorus on Aleppo’s southwestern outskirts. Konashenkov said the discovery proves the militants have used chemical weapons.

However, the Syrian National Coalition, a main opposition group, denied that rebels used chemical weapons in Aleppo, saying that the shells that were fired are similar to those used by government forces.

The SNC called on UN organizations to open an investigation into the case. Russia is asking the Organization for the Prohibition of Chemical Weapons, an international watchdog group, to send its experts to the site.

Associated Press