U.N. Special Envoy for Syria Staffan de Mistura said that reports of a gas, believed to be chlorine, being dropped on Aleppo on Thursday are being investigated.
“There is a lot of evidence that it actually did take place”, he told reporters, adding that if confirmed the attack would amount to a war crime.
On Wednesday, at least three people were killed when a gas, believed to be chlorine, was dropped on a neighborhood in the Syrian city of Aleppo, according to a hospital and a local rescue group.
The Syrian Civil Defence, a volunteer rescue group operating in opposition-held areas, told Al Jazeera it had recorded three deaths and at least 25 injuries after a barrel containing a gas suspected of being chlorine fell on the Zubdiya neighborhood of opposition-held Aleppo.
“At about 7:30 pm on Wednesday, an explosive barrel was dropped from a helicopter on the Zubdiya neighbourhood. One woman suffocated to death due to gas inhalation, along with her 10-year-old daughter and four-year-old son,” Khaled Khaled, an Aleppo-based member of the rescue group, told Al Jazeera.
The group, also known as the White Helmets, said it could not independently verify the nature of the gas.
Hamza Khatib, the manager of Al Quds hospital in Aleppo, told a Reuters news agency photographer that the hospital had recorded four deaths from gas poisoning and 55 injuries.
Russia said on Wednesday there would be daily three-hour ceasefires in Aleppo starting Thursday to allow humanitarian convoys to enter the city safely, a proposal which the United Nations mediator said was “not enough”.
U.N. humanitarian adviser Jan Egeland said Thursday that a 48-hour pause was required to ensure safe deliveries, adding: “What is the new and positive thing today is that the Russian Federation said they would like to sit down with us and the other co-chair (the United States) to discuss how the U.N. proposal could be implemented. We are hopeful that will lead to something.”