Syrian Information Minister Omran al-Zoubi slammed the armed groups firing of a chemical rocket in northern Aleppo province as "dangerous escalation."
Such move mirrors the shift in using the arms that are being sent through neighboring countries to the opposition fighters, the state-run SANA news agency quoted Zoubi as saying.
The remarks were carried by the state media just an hour after the SANA splashed a thick red urgent news bar accusing the opposition fighters of firing a rocket stuffed with chemicals at Khan al-Asal town southwest of Aleppo.
"In today's crime, the terrorists have used an internationally- prohibited weapon," Zoubi said, reiterating that the attack is the first achievement of the would-be interim government by the opposition.
Spelling further information about the controversial attack, Zoubi said that 16 people were killed and another 86 wounded.
He added that the rocket has been fired from Aleppo rebellious area of al-Nairab.
The minister held the international community and the countries supporting the rebels responsible for the attack, mainly naming the governments of Turkey and Qatar.
Zoubi meanwhile stressed that the situation on ground and the morale of the Syrian army is good.
Media reports cited medical sources in the area as reporting that hospitals have received cases with suffocation and toxicity due to exposure to unknown gases believed to be loaded on rockets' head.
Khan al-Asal town, southwestern outskirts of northern Aleppo province, has been a scene of intense fighting between the government troops and rebel fighters in a bid to storm the town due to its strategic importance.
According to local media, the rebels had managed to storm the town and taken control over a police academy there, before the Syrian troops waged a wide-scale offensive and recaptured the area last week.
The file of chemical weapons in Syria has emerged lately with western and Israeli officials expressing fears that the country's chemical weapons may fall in the "wrong hands," in reference to the radical rebels affiliated with al-Qaida who are fighting in Syria under the title of Nusra Front.