Syrian government forces have been accused of a chlorine gas attack in the Syrian city of Aleppo. No deaths were reported but at least 70 people suffocated.
Some in hospital have been given oxygen masks to help them breathe. An inquiry partly conducted by the United Nations last month found that Syrian government forces were responsible for two toxic gas attacks involving chlorine in the past two years.
The government has denied the accusations, and couldn't be reached for comments on the recent attack.
The Civil Defense accused the government of two other suspected chlorine gas attacks in August that the United Nations Commission of Inquiry on Syria is reportedly investigating.
"Unimaginable crimes are occurring in Aleppo ... pro-government aerial bombardments cause mass civilian casualties," Commission Chairman Paulo Pinheiro told reporters in Geneva. "In government-held areas, indiscriminate ground shelling (by) armed groups ... is also killing scores of civilians," he added.
The five-year-old conflict in Syria has killed more than 250,000 people and forced more than 11 million from their homes.