Dozens choke in Aleppo after barrel bomb attacks

Dozens of people had to be treated for breathing problems in the Syrian battlefront city of Aleppo after regime helicopters dropped barrel bombs on a rebel-held district on Tuesday.

The Britain-based Syrian Observatory for Human Rights said the bombs hit the Sukkari neighbourhood and that more than 70 people, "most of them civilians", were left choking and needed treatment.

The opposition Aleppo Media Centre said on its Twitter account that Sukkari was the target of a chlorine attack.

Observatory head Rami Abdel Rahman was unable to confirm the claim but said that no one was killed in the strikes.

A Sukkari resident told AFP a "very strong smell" filled the neighbourhood after it was hit by a barrel bomb and that he and others had difficulty breathing.

Both sides in Syria's complex war have traded accusations of attacks against civilians and use of unconventional weapons including chlorine and mustard gas.

Last month, an investigative panel set up by the UN Security Council said in a report that President Bashar al-Assad's forces had carried out at least two chemical attacks, one in 2014 and another in 2015.

But Syria's ally Russia said it had "very serious questions" about the report while the Syrian envoy to the world body, Bashar Jaafari, rejected the findings.