Most of Hezbollah's rockets are short range Katyusha rockets, which refers not to a specific model but is a general term for short-range unguided rockets fired in large quantities from trucks. The term "Katyusha" is usually used to refer to 122 mm BM-21 rockets, and sometimes includes BM-27 Uragan and Fajr-3 rockets as well. and In addition to their Katyushas, Hezbollah has "thousands" of medium-range rockets like the Fajr-3 and Fajr-5 and "hundreds" of long-range rockets. Although Hezbollah's long range rockets can be based farther from the border and threaten more of Israel, they also require large truck-based Transporter erector launchers that are very vulnerable to air strikes. Hezbollah's long range rockets were top priority targets for the IAF in the 2006 war and the IAF destroyed 18 of 19 to 21 of Hezbollah's Zelzal launchers, and Hezbollah never used the rocket during the war. Similarly, the group lost over half of their medium-range Fajr-3 and Fajr-5 rockets in the first hour of the war. Considering that Hezbollah invested enormous effort in acquiring these rockets, their almost total destruction in the war represents a major failure. Hezbollah's small Katyushas rockets are somewhat man-portable and more survivable. Hezbollah has since reportedly buried their rockets in rough mountain regions of Lebanon farther from the Israeli border, which could complicate IAF efforts to find and destroy them. Hezbollah mostly fires BM-21 rockets individually, but sometimes fires them in groups. There is some evidence that Hezbollah indigenously builds IRAM rockets, combining the rocket of a 107 mm munition with the warhead of a Falaq-1 rocket, which are informally called "Volcano" rockets. These are particularly used in Syria. Many Hezbollah rockets are stored underground in a "ready-to-fire" mode. There is no consensus on how many rockets Hezbollah has in total, and while estimates of around 150,000 are commonly repeated, Jane's calls this propaganda. There is agreement that Hezbollah's rocket force is extremely large and has expanded substantially in the last decade.