The US and Israel have repeatedly, and correctly, stressed that Iran and Syria are directly behind Hezbollah's recent actions.
The clearest sign of this was the rocket attack on Haifa. Ha'aretz reports that the missiles were of the Fajar model. What the article fails to mention is that the Fajar is an Iranian built rocket with a range of 45-75 kilometers. More info on the rocket here (the article entitled: albawaba.com: Israel Fears Hizbullah Rockets) and here.