DEBKAfile reports from western military sources that present in the rocket which exploded in the Aleppo neighborhood of Khan al-Assal Tuesday March 19 were phosphorus, chlorine and Agent 15 or BZ. Although the Assad regime and the Syrian rebels charged each other with firing the rocket, which killed 15-31 people and injured more than a hundred, it was not possible to verify which side was responsible. The White House denied it was the rebels, while Moscow backed Damascus by insisting that it was.