°®Âþµº

The Britain-based Syrian Observatory for Human Rights reported a "foul smell after regime helicopters struck several areas of the town in Idlib province, causing five civilians to suffer from suffocation".

It quoted residents and medical sources as saying "toxic gas" was used in the attack, without elaborating. 

Local sources said gas was believed to be chlorine and put the number of injured at nine, including three members of Syria’s civil defence force White Helmets. The video of the aftermath of the attack showing choking survivors was shared on social media.  

The five airstrikes resulted in the collapse of several buildings, as the White Helmets continue to rescue civilians from the rubble. 

Syrian regime air strikes also killed six civilians in the town of Kafr Nabi, near Maarat al-Numan in the southern countryside of Idlib province.  Four other civilians were killed in regime bombing on Maaret al Numan and Maasarin.

The Observatory also said that "airplanes believed to be Russian hit the main hospital in Maaret al Numan causing damage".

Local sources told °®Âþµº that the hospital was targeted by six airstrikes, two with burning napalm. The raids damaged the entire hospital, including a paediatric ward where dozens of children were rescued. 

The sources added that a similar bombardment had targeted a specialist surgical hospital in the city of Kranabel, south of Idlib, which also lead to the hospital suspending its services.

The National Coalition for Revolutionary forces and the Syrian Opposition issued a statement on Sunday evening demanding the UN Security Council intervene immediately to "stop Russian crimes in Syria".

The latest developments come as the United States this week accused the Syrian regime of using chemical weapons on opposition forces near the capital Damascus.

The Syrian foreign ministry denied the accusations as "lies".

US Defence Secretary Jim Mattis told reporters on Friday his government was concerned sarin gas  may have been recently used in Syria, citing reports from NGOs and rebel groups. These reports said toxic gas has been used.

Matis however said the United States has no proof to support these accusations.

Last month, 21 people were treated for respiratory problems after rockets were fired on the rebel bastion of Eastern Ghouta outside Damascus.

Agencies contributed to this report