Civil defense groups in Syria have accused Bashar al-Assad of using chlorine gas in at least 35 attacks on civilians since mid-March, the Guardian reports. “Whenever the regime loses an area or a city it arbitrarily takes revenge on civilians,” said White Helmets’ leader Raed Saleh. “It is targeting civilians.”

Since March 16th, Syrian civil defense workers and doctors have recorded 35 attacks in which they allege chlorine was used, resulting in more than 1,000 injuries and nine deaths. It is believed, the Guardian reports, that the Assad regime is lacing barrel bombs with chlorine, which are then dropped on civilian targets in Idlib province, which was taken in March by a coalition of rebels backed by Saudi Arabia and Turkey.

The Syrian Observatory for Human Rights reports that the Assad regime’s air force has launched more than 2,000 attacks on Idlib since it fell to to the rebels. “Most of the targeting is of civilian areas, and most of the injured are women and children,” Muhammad Tennari, the manager of Sarmin hospital told the Guardian. “It’s almost daily now.”

“The children who came to us were suffocating and we couldn’t do anything because they had breathed too much chlorine,” Tennari said. “It’s very distressing to see children suffocating in front of you and you cannot do anything.”

“The key issue is the present and the lack of steps that the US and Russia—the two architects of the chemical weapons deal in Syria—have taken to stop chlorine attacks in Syria,” Human Rights Watch’s deputy director for the Middle East and north Africa Nadim Houry said.

“So far, Russia is refusing to even name the culprit, while the US condemns but otherwise tolerates Assad’s ongoing violation of global norms against chemical warfare.”

Chlorine is banned under the 1993 Chemical Weapons Convention. “This dithering in not referring the regime to the international criminal court gives it an opportunity to kill more civilians with these weapons,” said Saleh.

Photo credit: AP Images. Contact the author of this post: brendan.oconnor@gawker.com.