While the exact cause of the deaths remained unclear, there was widespread agreement, as one European expert noted, that “something terrible has happened.’’
If confirmed, the use of toxic agents would be the most serious in decades, presenting a renewed challenge to President Obama, who said last year that the use of chemical weapons in Syria would constitute a “red line” requiring a U.S. response.
The Syrian government strongly denied responsibility. But a White House statement put the blame squarely on Syrian President Bashar al-Assad, referring to “reports that hundreds of Syrian civilians have been killed in an attack by Syrian government forces, including by the use of chemical weapons.”
French Foreign Minister Laurent Fabius said the international community should respond “with force” if the allegations are proven true, news services reported.
The deaths touched off a vigorous debate among independent experts about whether available information pointed to the use of a well-known chemical weapon such as the nerve agent sarin or to some other toxic agent. U.S. intelligence agencies offered no early verdict.
The attack came as U.N. investigators were already on the ground in Syria to investigate previous incidents in which the United States and its allies have said small quantities of chemical weapons were used. But the U.N. Security Council was unable to agree Wednesday on whether those experts should immediately investigate the new incident.
The Russian government, Assad’s strongest supporter, suggested that the opposition itself had staged the attack in a “pre-planned provocation.’’
Witnesses said the attack began when Russian-made Grad rockets began falling at around 2 a.m. in neighborhoods east of the capital where rebels have had some recent success in repelling government forces.
Sama Masoud, an opposition activist who lives in one of the targeted neighborhoods, described scenes of chaos on the streets as panicked residents did not know whether to stay in their homes or flee.
“The fiance of my sister has died,” she said. “My friend, her husband and her husband’s uncle — all dead while asleep.”
More than 130 videos were posted online showing the victims. In some, children lay on tiled floors, vomiting, convulsing and struggling to breathe as they were treated with hand-held respirators or as medics desperately administered chest compressions.
In others, men sprawled on the floor of a makeshift hospital were hosed down with water in what appeared to be a desperate attempt to wash off the remnants of the poisonous gases.