On a day Syrian forces were accused of massacring civilians, U.S. officials said Israeli war planes conducted airstrikes inside Syria Friday. The unnamed U.S. officials told NBC News the Israeli attacks were believed to have targeted delivery systems for chemical weapons headed for Hezbollah in Lebanon. An Israeli spokesman in Washington declined to comment on the specifics of the airstrikes. However, he said, "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." White House officials deferred to the Israelis regarding comment on the attacks. NBC noted it would be the second time this year Israel tacked inside Syria, the last time coming in January when a convoy of anti-aircraft missiles believed on their way to Hezbollah was destroyed.