Those weapons could have been used by Al-Asad forces.However, we need to verify whose weapons they were and where they came from. Did they come from Russia ,or Iran ,or Israel ? Any of these are capable of leashing death in Syria.
Man shot dead in northern Israel town of Bi'ina, police say the murder was gang related (Haaretz)
from the article: U.S. official: Syrian government 'clearly' behind chemical attack