Iran got the Zelzal-2 into production about ten years ago, after a decade of development effort. Iran received technical help from North Korea and China. The 3.5 ton rocket is 27 feet long, two feet (600mm) in diameter and carries a 1,300 pound warhead. Israel first detected Zelzal-2's in southern Lebanon four years ago. The Zelzal-2 is a solid fuel rocket, so it can be set up and fired in less than fifteen minutes. But because of its weight, it has to be carried by a truck modified to include a launcher.
A number of Iranian-manufactured Zelzal-2 surface-to-surface missiles (a knock-off of the old Soviet FROG-7) are reported to be in Hizbollah's inventory. Using an inertial guidance system, these missiles are reportedly accurate to under 100 meters at their maximum range, which is estimated to be about 200 kilometers, but thought by some to be more. This puts Tel Aviv in range of these missiles, when launched from southern Lebanon. And if launched from the West Bank territories (though at present there is no evidence that there are any of the missiles in the Palestinian territories), it could easily hit almost any part of Israel, including the nuclear research facilities at Dimona in the Negev. As a result, over the past two weeks the Israeli Air Force has been paying careful attention to hitting Zelzals, and has destroyed at least a dozen of them.