The United Nations will open an investigation into an alleged chemical weapons attack in Syria , U.N. Secretary-General Ban Ki-moon said Thursday.“The investigation will start as soon as practically possible,” Ban told reporters. The probe will be into an alleged chemical weapons attack Tuesday near the city of Aleppo.
He added that the investigation will look into “the specific incident brought to my attention by the Syrian government.” 
Ban said he was aware of other allegations of the reported use of chemical weapons, but did not make clear whether these would be part of the investigation.The secretary-general said he hopes the mission “will contribute to ensuring the safety and security of chemical weapons stockpiles in Syria.”Ban said the investigation will start “as soon as practically possible” but “will not happen overnight.”He said full cooperation from all sides will be essential and stressed that this includes “unfettered access.”
Britain, France and the United States called on Wednesday for a United Nations inquiry into accusations by the Syrian government and the opposition of chemical weapons attacks.
London and Paris cited Syrian opposition claims that there were two chemical weapons attacks, one in Damascus and another in Aleppo, on Tuesday and demanded that both be investigated.
But Russia, President Bashar al-Assad’s last major ally, insisted at a U.N. Security Council meeting that only the government’s allegations should be investigated.
Syria has asked the United Nations to order an “independent” investigation into its claim that opposition rebels used chemical weapons in an attack at Khan al-Assal near Aleppo on Tuesday.
Divisions over the two year-old Syria conflict again erupted at a Security Council meeting where France raised the allegations.