A lob bomb (known officially as an improvised rocket-assisted mortar, improvised rocket-assisted munition, or IRAM) is a rocket-fired improvised explosive device made from a large metal canister (usually a propane gas tank that has been drained of its contents and filled with explosives, scrap metal, and ball bearings), which has been used by insurgents and coalition forces during the Iraq War since late 2007. The weapon is essentially an airborne version of an improvised explosive device.
Lob bombs are propelled by 107 mm rockets and launched, several at a time, from the backs of small trucks where they are arranged in rows, sometimes by remote control (using a signal from either a cell phone, cordless phone, command wire, or other forms of remote control device). They are typically launched in an arced trajectory, which enables them to be aimed over walls that enclose opposing bases and other military facilities, in a similar manner to a conventional mortar. The weapon is believed to be highly inaccurate, and unofficial estimates place the range of lob bombs used so far as being between 50 and 150 yards (approx. 45 to 140 m).
According to U.S. military officials, lob bombs are designed to cause "catastrophic damage," and have the ability to kill "scores of soldiers" at once, more than conventional improvised explosive devices. As of July 12, 2008, out of 11 lob bomb attacks on American bases, three U.S. soldiers had been killed and 15 had been wounded, all three deaths occurring in an April 28, 2008, attack on a U.S. base in eastern Baghdad.
So far, the weapon has only been encountered in Baghdad, where it appears to be used by Shiite militias, whose superior ability to conceal forensic evidence about their identity has been acknowledged by the U.S. military. The U.S. military has found that the rockets used to propel the lob bombs have been produced in Iran, Russia, and China. One media report  indicates such a munition may have been used by the Taliban to bring down a Chinook helicopter in Afghanistan on August 6, 2011.
Such devices were first described in the international media in July 2008. In July 2008 Major General Jeffery Hammond, the commander of the 4th Infantry Division and commander of U.S. forces in Baghdad, called the lob bomb "the greatest threat right now that we face."
The type of improvised launch system and a rocket is not new to warfare. The Provisional Irish Republican Army developed a similar system during the Troubles. It was used in the February 1991 attack on 10 Downing Street, the London office and home of the British prime minister.
As of 2011, it has also been used as far out as the Iraq Iran border by Iran backed Hezbollah forces to attack US Military installations across the country. Combat Outpost Shocker was hit in 2011 by several of these devices killing 3 Soldiers, wounding several others and severely damaging the HQ facilities of the outpost. While the attack did not hinder operations in any way, it did perform its task of what it was designed for exactly as it was meant to. These bombs are now also being used in Afghanistan and several other locations around the world, some have been found in terror cell bomb making facilities in the United States by the FBI and ATF, and they are being used by ISIS on anyone who is not for or actively supporting ISIS.
Lob Bombs were used during the Vietnam war by the VC/NVA, specifically in Operation Oklahoma Hills, 1 March to 29 May 1969. Below is a part of the After Action Report by the Col. R.L Nichols, Regt CO, 7th Marines that describes this device and how it was used. "During the period 25 April to 27 May, there were four reported incidents of the enemy employing five “Lob Bombs” against positions on Hill 55 (there were two other reported incidents occurring outside the OKLAHOMA HILLS AO during the same period.) The first LOB BOMB spreads were directed at the rear billeting area temporarily occupied by the 3rd battalion, 26th Marines on finger 3, Hill 55 (AT973614) 252300H April 1969. The bomb consisted of 1 250 lb low drag bomb which had been refused to utilize an NVA # 8 fuse... and propelled a distance of 600 meters from a launch site located SE of the impact area. On this occasion, a low air burst occurred resulting in a maximum fragmentation dispersion. …Casualties from these four launches were 1 KIA and 28 WIA. Analysis of the launch and impact craters were conducted … 14 May when a .. demonstrated… lob bomb technique showing how the propelling charge (a quart sized or number 10 can packed with explosives) was placed under the center of gravity of the projectile and detonated. Subsequent filed testing by personnel from the Division G-2 section resulted in more definitive performance parameters. The range which dud ordinance can be propelled my exceed 1000 meters and there appears to be no practical size limitation to the ordinance being propelled (a 750 lb bomb was reported being “lobbed” at an ARVN Ranger position) although the most commonly projected ordinance have been 105mm artillery duds and 250 lb low drag bombs. (A more detailed report on the construction and employment of the “lob bomb” is contained in 1st MarDiv Special Intelligence Bulletin dated 26 May 1969." 
- Barrack buster
- Barrel bomb
- Explosively formed penetrator
- Improvised artillery in the Syrian Civil War
Texas Tech University The Vietnam Center and Archive, Item Number: 1201051002
- "'Lob Bombs' Big Worry for US in Iraq - TIME". Time. Archived from the original on 2013-02-04.
- VOA News - Insurgents Using New Homemade Rocket Weapon in Iraq Archived 2008-07-12 at the Wayback Machine.
- Democracy Now! | Stop-Loss: A Look at the US Military Policy that Creates a "Backdoor Draft" to Force Soldiers to Continue Service
- Burns, Robert (July 12, 2008). "AP: 'Lob bombs' biggest worry for US in Baghdad". Fox News. Retrieved March 10, 2011.
- Defense Review - Baghdad: Improvised Rocket-Assisted Munitions (IRAMs) Arrays Can Kill over Walls
- Lob Bomb
- Axe, David (8 August 2011). "Did a New Taliban Weapon Kill a Chopper Full of Navy SEALs?". Wired.com Danger Room blog. Retrieved 8 August 2011.
- "Iraqi Day 🇮🇶 on Twitter". Twitter. Retrieved 2017-03-20.
- Texas Tech University The Vietnam Center and Archive, Item Number: 1201051002