NEW YORK // The United States is investigating whether Syrian regime forces are responsible for an alleged chemical attack earlier this month.

White House spokesman Jay Carney said the agent used in the attack in Kafr Zeita, a village in Hama province controlled by rebel forces, was a toxic industrial chemical, most likely chlorine.

“We’re working to determine what happened,” Mr Carney said on Monday. “And once that has been established, we can talk about what reaction, if any, or response, if any, there would be from the international community.”

The Syrian opposition claims that military helicopters dropped improvised barrel bombs containing chlorine gas on the village on April 11 and 12, and that these attacks were followed by poison gas strikes on Al Tamana’a in Idlib province on Friday and on Monday in Telminnes, a town near Kfar Zeita.

Syrian state media reported that chemical weapons were used in Kfar Zeita, but blamed Al Nusra Front, the Syrian Al Qaeda affiliate, saying that two people were killed in the Kafr Zeita attack and more than 100 injured.

The remains of the chlorine bombs bore distinctly similar characteristics to the barrel bombs the Syrian military regularly deploys and which no rebel groups are known to have in their possession, weapons analysts told Reuters.

A State Department spokeswoman said that US was working with the United Nations and the Organisation for the Prohibition of Chemical Weapons (OPCW) to obtain more details, but acknowledged that chlorine was not one of the priority chemicals that Syrian president Bashar Al Assad had agreed to hand over for destruction.

Mr Al Assad’s government is required to give up its chemical weapon stockpiles under a UN Security Council resolution passed in September after a chemical attack allegedly killed more than 1,400 people in a rebel-held suburb of Damascus.

The state department spokeswoman, Jen Psaki, declined to say whether the use of chlorine would be seen as a breach of the resolution, saying the investigation was only in its preliminary stages.

Chlorine, which has industrial uses and is far less lethal than poison gas such as sarin, was not known to have been weaponised by Syria at the time of the agreement last September and was not included on the list it submitted to the OPCW. If Damascus is using industrial chlorine gas as a tactical weapon across the country, it reveals a significant blind spot in the chemical weapons deal and raises the possibility that the agreement will fail to end chemical warfare in Syria.

Analysts doubt that a chlorine attack would prompt a military reaction from a US administration that has so far refused to become directly involved in the three-year war that has left more 150,000 dead. Military action would also threaten to derail the chemical disarmament process that officials describe as a major US achievement.

“What are they going to do, attack Syria now and take control of the country? Nobody in the West wants to take responsibility for Syria,” said Joshua Landis, director of the Center for Middle East Studies at the University of Oklahoma. “I don’t think [the latest attack] is going to affect US policy very much.”

A small number of moderate rebel groups have in recent weeks posted videos on YouTube showing fighters using sophisticated US-made anti-tank missiles against Syrian forces, and it has been reported that Washington is allowing allies who possess the missiles, such as Saudi Arabia, to supply them to vetted groups.

The US administration has previously been reluctant to give such weapons to the rebels, and has so far blocked the transfer of anti-aircraft missiles, out of fear they would fall into the hands of Islamist militants.

With counterterrorism concerns taking precedence, western officials also fear that if Mr Al Assad fell, Syria would become a Somalia-like vacuum dominated by extremists who would use it as a base to launch attacks abroad.

Rather than a softening of this position, Mr Landis said, the appearance of American anti-tank missiles is more likely an attempt to manage the US relationship with Saudi Arabia, which has frayed significantly during the past year over US policy in the Middle East.

“The US is trying to keep Saudi from going it alone and so to restrain them they need to give something and keep some skin in the game and keep the rebels limping along,” Mr Landis said.

“America has completely divorced itself from this situation and is focused on saving its reputation in the world by clinging on to international law and repeating empty mantras about transitional government in Syria, which is yesterday’s news,” Mr Landis said. “But [they] refuse to enable the opposition to win in any way, shape or form.”

tkhan@thenational.ae