"Al Nusra terrorists prepare car bombs filled with chlorine, white phosphorus and phosphates as well as Grad and Elephant rockets equipped with poisonous substances for attacks on residential areas of the city of Aleppo," Kazem said.
Earlier in May, the US State Department of State said Washington was collecting information regarding a chemical weapons attack in Syria that had allegedly been carried out by the Syrian government over the weekend.
READ MORE: Terror Chemical Attack Plotted in Syria's Idlib, Aleppo — Russian MoD
The Russian Defence Ministry said that Al Nusra militants were preparing to stage a provocation in Syria's Idlib province in order to thereafter accuse the Russian forces and the Syrian army of allegedly attacking civilians with chemical weapons.
*Al-Nusra Front is a terrorist group outlawed in Russia and many other countries.