BEIRUT -- Syrian state television and anti-government activists reported Saturday that poison gas had been used in a rebel-held village in the central province of Hama, with each side blaming its enemies for an attack that they both said sickened more than 100 people.
The attack took place Friday evening in the village of Kfar Zeita, sending streams of choking patients, including children, to poorly equipped field hospitals, according to local medics and videos posted online. Opposition activists said government helicopters had dropped improvised bombs on the village, covering it with a thick smoke that smelled of chlorine.
While the opposition reported the attack soon after it happened, Syrian state television first mentioned it the day after in an urgent news banner during a broadcast. It blamed the Nusra Front, al-Qaida's affiliate in Syria, for the attack, adding that two people were killed and more than 100 others affected by the gas. A subsequent banner announcement said the Nusra Front was preparing two more chemical attacks. It was the first time since last year that both sides agreed that toxic weapons had been used.
On Aug. 21, 2013, sarin gas attacks in suburbs of Damascus killed hundreds and led President Barack Obama to threaten airstrikes on Syrian government targets. The strikes were averted by a deal to dispose of Syria's chemical weapons stockpiles. Western officials say there is clear evidence that the government carried out the August strikes, while the government blames insurgents.
Allegations of a new attack carry high stakes. If the government used toxic arms now, that would suggest that it felt it could act with impunity because of international reluctance to punish it militarily. Since the Aug. 21 episode, government tactics like starving rebel areas and bombing residential neighborhoods have continued unabated, killing many more people than chemical weapons have. But the killings have produced little international response beyond a U.N. Security Council resolution calling for an end to the violence and for increased access for groups providing humanitarian aid.
For the opposition, Mr. Obama's decision not to bomb Syria, after calling chemical weapons use a "red line," reinforced the feeling that the international community would do little to stop the violence.
In one video posted online Saturday from Kafr Zeita, a man walking over rubble from a recent bombing shouted at the activist documenting the destruction: "There is no point in filming. No one responds."
The Syrian National Coalition, an opposition group, called on the United Nations to conduct a "quick investigation into the developments related to the use of poisonous gas against civilians in Syria." The coalition also claimed that another chemical weapons attack Friday struck the Damascus suburb of Harasta, though state media did not report on it.
Syrian officials, meanwhile, have blamed insurgents for chemical attacks and say they have intelligence indicating that they plan to use them again.
Western officials say there is no indication that insurgents have toxic weapons, though they do not rule out the possibility that some extremists could seek them, particularly toxins like chlorine that are easier to handle than sarin.
Numerous attacks reported by the government's opponents in the months before August 2013 produced hard-to-classify symptoms and killed few people, raising speculation that low doses of banned chemical weapons or high concentrations of riot-control gases were used.
Some of those attacks were also reported by Syria's state media, which blamed insurgents, while others went unacknowledged by the government.
On Saturday, anti-government activists posted a video showing a helicopter dropping a large object, resembling a barrel bomb, over Kfar Zeita at sunset on Friday, producing a large explosion. Several witnesses said the symptoms began to occur then.
Numerous videos posted online by anti-government activists showed several men struggling to breathe and being given oxygen, as well as children lying on a medical table, some appearing ill and others crying.
"The smell was like chlorine or toilet bowl cleaner, but the symptoms faded directly within two hours," Nazih al-Ghazi, who was working in the village's field hospital, said in a Skype interview.
Dr. Ghazi said the symptoms included a severe cough, difficulty breathing, blue lips and foaming at the mouth. He called for additional resources, saying the hospital was short of oxygen.
Chlorine, one of the most commonly manufactured chemicals in the U.S., is used to purify drinking water. But as a gas, it can be deadly, with the German army using it in warfare in World War I. The Geneva Protocol of 1925, which Syria signed, banned its use in battle.
Associated Press contributed.