White House warns of 'consequences' if Syria has used a chemical weapon

The White House on Tuesday warned there would be “consequences” for the regime of Syrian President Bashar al Assad if it has crossed President Obama’s “red line” and used a chemical weapon.

Press secretary Jay Carney declined to confirm reports that a chemical weapon has been used for the first time in Syria’s civil war, saying only that the White House is "looking carefully at the information as it comes in."

But Carney did say there was "no evidence" to substantiate allegations from the Assad regime the chemical weapon attack came from rebel forces.

Syrian state media said that 16 people were initially killed by a rocket containing chemical materials in the town of Khan al-Assal near Aleppo on Tuesday, and 86 were injured. The state-run Syrian Arab News Agency said the death toll had risen to 25.

The Syrian government and opposition forces blamed each other for the attack.

“We were hearing reports from early this morning about a regime attack on Khan al-Assal, and we believe they fired a Scud with chemical agents,” senior rebel commander Qassim Saadeddine told Reuters by phone from Aleppo.

The White House did not rule out the possibility that the Assad regime waged the attack, and warned there would be "consequences" if they are found to have done so.

"We have been very clear about our concern that as the Assad regime is increasingly beleaguered … that it will consider the use of chemical weapons against the Syrian people," Carney said, stressing that the administration was "obviously treating this as a serious issue."

Pressed on what kind of consequences could result from a chemical attack ordered by the Syrian government, the press secretary said he "wouldn't care to speculate," but read from a speech Obama gave at the National War College in December.

"The use of chemical weapons is and would be totally unacceptable," the president said at the time. "And if you make the tragic mistake of using these weapons, there where be consequences, and you will be held accountable."

Carney did say that the level of assistance to the Syrian opposition could be altered, depending on the findings of intelligence assessments.

"We are constantly assessing our programs of assistance to the Syrian people and the Syrian opposition," Carney said.

The use of chemical weapons in Syria could escalate the two-year conflict and draw greater involvement from the United States. President Obama has said the use of chemical weapons by Assad’s forces is a “red line” that would prompt U.S. action.

Syria’s government has not confirmed it has chemical weapons, but officials have said they would only be used in a potential scenario against foreign fighters, not Syrians.

A Reuters photographer on the scene said that he saw “mostly women and children" hit in Tuesday's blast. 

"They said that people were suffocating in the streets and the air smelt strongly of chlorine," the photographer said.

This story was first posted at 10:57 a.m. and has been updated.