A neighborhood in the Syrian city of Aleppo, which is held by Kurdish YPG militias, has been shelled with chemical agents from territory held by Islamist and FSA factions, a local journalist on the ground has told to RT.

“The attack was carried out between 11.30 and 12.00 local time. The gas that was used in this attack, caused choking and malaise among those affected. This indicates that the poisoning substances were used in the attack,” journalist Nawrouz Uthman reports.

Uthman adds that 23 people were killed and over 100 injured in Thursday, April 7’s attack.

Video filmed by the journalist shows yellow gas rising over the Sheikh Maqsood neighborhood.

The Kurdish Red Cresent has confirmed the reports alleging that a chemical weapons attack took place.

Walaat Mamu, doctor at a local hospital, said that several victims came to the hospital with symptoms of suffocation after the shelling.

A video shot in the Sheikh Maqsood neighborhood shows several men experiencing difficulty breathing and a voice behind the camera saying there was a chemical attack in the area.

Kurdish journalist Kovan Direj reported that civilians and People's Protection Units (YPG) fighters had been exposed to yellow smoke. He said nine civilians were killed and 29 injured in the shelling.

The Russian Defense Ministry said on Thursday that more than 1,000 Al-Nusra militants, along with seven tanks and 24 all-terrain vehicles armed with heavy machine guns, are currently based on the northern outskirts of Aleppo.

The Russian military also stated that, over the past 24 hours, Islamic State (IS, formerly ISIS/ISIL) and Al-Nusra militants have been stepping up armed provocations against civilians and government troops in the area, which included an attempt to capture the village of Handrat.

Last month, Islamist fighters used yellow phosphorous in a chemical attack on the Sheikh Maqsood neighborhood, according to YPG.

The ceasefire in Syria came into force at midnight Damascus time on February 27. The truce does not cover groups officially recognized as terror-organizations by the UN Security Council, namely Islamic State and Al Nusra, as well as several others.