Israel confirmed that its warplanes had carried out an air strike in Syria, targeting a shipment of missiles reported to be destined for Lebanon.
Hundreds of Sunni Muslim families also fled the Syrian coast after massacres, reportedly carried out by government forces.
Tom Barton reports:
Israeli officials have confirmed that an air strike in Syria has been carried out targeting a shipment of "advanced missiles" believed to be bound to Hezbollah militants in Lebanon.
Meanwhile, President Obama said the US will not "leap before we look" over alleged use of chemical weapons.
Tom Savvides reports.
Israeli officials have confirmed an air strike on Syria, and said it targeted a shipment of advanced missiles, the Associated Press reports.
– A spokesman for the Israeli Embassy in Washington
We cannot comment on these reports, but what we can say is that Israel is determined to prevent the transfer of chemical weapons or other game-changing weaponry by the Syrian regime to terrorists, especially to Hezbollah in Lebanon.
Israel has conducted an air strike in Syria, apparently targeting a building, according to CNN, although there has not yet been any official confirmation.
The network said US officials did not believe Israel had targeted a chemical weapons facility. CBS News cited US sources as saying Israel targeted a warehouse.
But Syrian UN Ambassador Bashar Ja'afari told Reuters, "I'm not aware of any attack right now."
A White House spokeswoman referred questions on the CNN report to the Israeli government.
The Pentagon declined comment.
In Jerusalem, a Israeli military spokeswoman declined to comment.
President Barack Obama has said the US expects to find more evidence of the use of chemical weapons in Syria, but warned that rushing into the conflict could cause problems on the ground.
Obama added that the US is already engaged, on a day-to day basis, in trying to deal with the crisis
He said the US is investigating to "get a better handle on the facts inside of Syria".
Speaking at in press conference in Costa Rica, Obama added: "If there is the kind of systematic use of chemical weapons inside of Syria - we expect that we are going get additional, further evidence - at that point we will present that to the international community".
He went on to warn: "When we rush into things, when we leap before we look, then not only do we pay a price, but often times we see unintended consequences on the ground. It's important for us to do it right."
The US believes Israel has conducted an air strike into Syria, CNN has reported, quoting unnamed US officials.
The news network claimed US and Western intelligence agencies are reviewing classified data showing Israel is most likely to have conducted a strike between Thursday Friday, according to two US officials.
CNN report this was the same time frame that the US collected additional data showing Israel was flying a high number of war planes over Lebanon.