The #Syria Civil Defence, which claims to be a non-aligned group of search and rescue volunteers, has alleged that chemical weapons were dropped on a town near where a Russian helicopter was shot down.

33 people, mostly women, and children were allegedly poisoned with what is suspected to be chlorine gas in Saraqeb, a town in the rebel-held Idlib province.

A spokesperson for the Syria Civil Defense alleges that several medium-sized barrels were dropped from a helicopter. The Britain-based Syrian Observatory for Human Rights also claimed that barrel bombs were dropped on Saraqeb, and noted that a large number of civilians were injured. The group did not claim that the bombs were chemical weapons.

According to the BBC, Saraqeb may have been hit by a chemical attack in 2013.

Attack a response for a downed helicopter?

Saraqeb is close to where a Russian helicopter was downed, most likely by Syrian rebel forces, after returning from what the Russian government claims was a humanitarian mission. A Russian Mi-8 helicopter was shot down Monday by ground fire. All five Russian crew members were killed.

So far, no group has claimed responsibility for the attack. #Russia claims that the helicopter was delivering aid to Aleppo, where Russian and Syrian government forces are currently besieging rebel forces.

The rebels control the eastern portion of Aleppo but have largely been cut off from outside supplies.

Russian and Syrian government deny use of chemical weapons

The United States, other Western powers, and United Nations have alleged that chemical weapons have been used in the Syrian #war. The Syrian government led by Bashar Assad has been accused of using chemical weapons on both military and civilian targets.

The deadliest single chemical weapons attack occurred in eastern Ghouta in 2016. At least 1,429 people were killed, including 426 children. The weapon used was identified as sarin gas. Evidence of mustard gas use has also been found in Syria.

As of January 2016, Syria's declared chem weapons stockpile had been destroyed. The weapons were destroyed after the United States threatened to intervene in the Syrian conflict. It is possible that the Syrian government maintains chemical weapons in clandestine locations.

Rebel forces and the Islamic State have also been accused of using chemical weapons.