The ministry alleged that "certain states" had enabled the militants to get access to chemical weapons, and blamed the Syrian government for it.
Wounded people were taken to the hospitals in the cities, said the report, quoting Health Director in Aleppo Ziad Taha, adding that the poisonous gas used in the attack is likely to be the chlorine gas after observing the symptoms of the wounded people.
Russian Federation says it carried out air strikes on a planned buffer zone around opposition bastion of Idlib, a day after an alleged toxic attack on regime-held city.
The conflict has killed more than 360,000 people and displaced millions, according to the Observatory.
The air raids were the first to hit the area since Moscow and rebel backer Ankara agreed to set up the demilitarized area around Idlib in September to prevent a massive regime attack to retake the area.
Russian Federation on Sunday blamed Syrian insurgents for firing shells filled with chlorine gas at Aleppo, with the Defense Ministry saying the projectiles came from an area held by the Nusra Front.
He said the shelling came from an area of the buffer zone controlled by the jihadist-dominated Hayat Tahrir al-Sham (HTS) alliance.
Syrian rebels have dismissed government accusations they used poison gas to attack government-held Aleppo city.
Since early morning the Assad regime and Iranian-backed groups have been shelling and firing rockets towards Idlib's Jarjanaz and al-Tamanah towns and Hama's al-Lataminah and Kafr Zita districts.
Turkey's defense ministry said in a statement Sunday that Defense Minister Hulusi Akar spoke with his Russian counterpart Sergey Shoygu about the recent developments in northern Syria.
More than 100 injured in Aleppo in gas attack - Syrian state media
"The resistance forces do not have chemical weapons or the ability to hold them", the rebel leader said, arguing that Assad's regime launched the offensive in order to incriminate the rebel groups.
State media showed images of Aleppo residents being treated in hospital as they struggled to breathe.
A rebel coalition on Sunday denied any involvement.
"We cannot know the kinds of gases but we suspected chlorine and treated patients on this basis because of the symptoms", said Zaher Batal, head of the Aleppo Doctors Syndicate.
In the neighboring Idlib region rebels are still in charge.
According to the Russian Defense Ministry, the seized chlorine canisters were later transported to the south of Aleppo province and handed over to terrorists of the Daesh-linked Hurras al-Din group.
Over the course of Syria's seven-year war, global human rights groups have repeatedly accused belligerents - especially the regime - of carrying out chemical attacks.
A year ago and in April, the allegations caused the United States to carry out punitive strikes in Syria.
In its message, the Syrian Government demands from the UN Security Council to immediately condemn such terrorist crimes and calls on it to assume its duties of keeping worldwide peace and security.
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