Israeli officials said there was "compelling evidence" that chemical agents were used in an attack against civilians in northern Syria earlier this week, citing satellite imagery and reports from the ground.
“It’s clear, at least to us in Israel, that chemical weapons have been used against civilians by the rebels or the government," said Yuval Steinetz, Israel’s minister for strategic affairs, in an interview with Israel’s Army Radio Wednesday.
On the same radio network a few hours later, Justice Minister Tzipi Livni said that Israel was "absolutely sure," but offered few details.
Meanwhile, CBS News quoted an unidentified American official late Thursday afternoon as saying that the U.S. was not certain that chemical weapons had been used in Syria, although it wasn’t ruling out the possibility.
But an Israeli intelligence officer, who was not authorized to speak publicly about the incident, said Israel was still investigating the type of chemical agents and trying to “pinpoint their source,” but that the substance affected the respiratory systems of the people who were exposed.
The officer said that Israel was certain that chemical was not one of the suspected deadly toxins in Syria’s chemical arsenal, such as sarin gas, a nerve agent. He said that he was aware of conflicting reports over who had deployed the chemical agents.
"It could have been the rebels, though we are very doubtful about that,” he said. “It could have been the regime, which is more likely. Or it could have been an accident. An area where chemical agents were being stored could have been bombed or improperly secured. All of these scenarios are possible, and we won’t know more until a thorough investigation is conducted."
Israeli security officials said they were sharing their information with the U.S. "in real time" and that the issue would feature prominently in meetings between Israeli Prime Minister Benjamin Netanyahu and President Barack Obama, who is visiting Israel this week for the first time since he entered the White House.
Syria’s government and the opposition forces fighting to topple Syrian President Bashar Assad have traded accusations over the alleged attacks, with each claiming that the other was responsible. The National Coalition of Syrian Revolutionary and Opposition Forces said that the attacks killed 19 people and that more 60 were hospitalized in two separate incidents, one in the Khan al Assal area north of Aleppo and another in the Ataybah suburb of Damascus.
The United Nations has asked the Organization for the Prohibition of Chemical Weapons to take part in an investigation, which the U.S., the European Union and other countries said they also are independently pursuing. In a speech Thursday, Obama said that if chemical agents were being used, he had no doubt that it was the regime and not the rebels.
"Assad has lost his legitimacy to lead by attacking the Syrian people with almost every conventional weapon in his arsenal, including Scud missiles," the president said, in a joint press conference Wednesday with Netanyahu. "We have been clear that the use of chemical weapons against the Syrian people would be a serious and tragic mistake."
Obama also expressed concerns that chemical weapons or advanced weapons systems could fall into the hands of dangerous parties as the civil war in Syria raged. He warned the Syrian president that he would be held accountable for his country’s weapons stockpiles.
Israeli officials have expressed increasing concern over both the transfer of conventional weapons to the militant Hezbollah movement in Southern Lebanon and the possible seizing of weapons by Islamist groups fighting in Syria.
Retired Israeli Brig. Gen. Michael Herzog said that it was very likely that Netanyahu also could ask for Obama’s support in using force to stop weapons convoys in Syria from reaching neighboring countries.
"It is widely reported that Israel hit a convoy of SA-17 missiles already, and I wonder if there is going to be more of these strikes by Israel," he said.
Israeli officials said they there was increasing evidence that hard-line groups were assuming control of Syrian towns near the border with Israel’s Golan Heights. The Syrian Observatory for Human Rights, a British-based monitoring group, said that rebels had taken several towns near the mountainous border area with Israel.