The United States was the first to use fuel-air explosives in the Vietnam War, dropping them by air to clear helicopter landing zones and minefields, and later deploying them as offensive weapons. In 2002, attempting to hunt down Osama bin Laden in the rugged mountains of Tora Bora, U.S. aircraft deployed thermobaric warheads on precision-guided missiles. The warheads would suck the oxygen out of the caves that Taliban fighters were hiding in.

The TOS-1 Buratino is a unique Russian self-propelled multiple rocket launcher system (MRLS) that has seen action in global hotspots like Afghanistan, Chechnya, Iraq and Syria. Like the enormous 240-millimeter 2S4 self-propelled mortar, the TOS-1’s specialty is obliterating heavily fortified positions. Although some of these may be found in rural rebel strongholds and fortified caves, they have often been employed in heavily urbanized environments. It’s gained a uniquely nasty reputation because of the horrifying effects of its fuel-air explosive warheads.

Recommended: Who Swallows North Korea after it Collapses? 

To put it concisely, these are amongst the most devastating explosive weapons short of tactical nuclear weapons.

Fuel-Air Explosives

TOS stands for “heavy flame thrower,” which is only accurate in a literal sense: instead of projecting a stream of jellied gasoline, the TOS-1 launches a rocket carrying a fuel-air explosive (FAE).

Recommended: Russia Had a Plan to Build the Ultimate Battlecruiser. 

These were first employed by the United States in the Vietnam War because napalm wasn’t destructive enough. Napalm munitions disperse a sticky, flaming liquid over a wide area. By contrast, a fuel-air explosive detonates the very air itself: a small explosive inside the FAE munition spreads a chemical cloud in the air through an aerosol effect. The gaseous cloud seeps effortlessly into buildings and caves, and down into slit trenches. A secondary explosive then ignites the cloud, causing a massive and long-lasting explosion.

Recommended: EMP Detonation, Nuclear Blast or ICBM Test? What is North Korea's Next Move?

While the heat generated by FAEs causes lethal burns in a wide radius (roughly two hundred by three hundred meters) the overpressure created by the sudden combustion of the air is even deadlier. The fiery blasts create a partial oxygen vacuum that kills and maims in a variety of grotesque ways and cannot be mitigated with body armor or hard cover.

The pressure generated by a TOS-1 blast amounts to 427 pounds per square-inch—for comparison, most conventional bomb blasts create roughly half that amount, and regular air pressure is fourteen pounds per square inch. Victims near the center of a TOS-1 blast radius are crushed to death. Further out, the overpressure can break bones, dislocate eyes, cause internal hemorrhaging, and rupture eardrums, bowels and other internal organs. It also sucks the air out of victims’ lungs, possibly causing them to collapse, leading to death by suffocation.

The United States was the first to use fuel-air explosives in the Vietnam War, dropping them by air to clear helicopter landing zones and minefields, and later deploying them as offensive weapons. In 2002, attempting to hunt down Osama bin Laden in the rugged mountains of Tora Bora, U.S. aircraft deployed thermobaric warheads on precision-guided missiles. The warheads would suck the oxygen out of the caves that Taliban fighters were hiding in.

The Soviet Union adopted the weapons shortly after the United States did, using them in a border skirmish against the Chinese in 1969, and employing both air-dropped and ground-launched FAEs on a large scale in the war in Chechnya. The proliferation of TOS-1 systems through global conflict zones (detailed below) ensures they will continue to see use in combat.

Rocket-Launching Tanks

Most of Russia’s artillery weapons use a light armored vehicle chassis like that of the MTLB armored carrier. The forty-six-ton TOS-1, on the other hand, uses the much heavier hull of a T-72 tank. There’s a good reason: the original TOS-1 model only had a range of around three kilometers, meaning it would have to withstand hostile fire from all kinds of enemy weapon systems.

The TOS-1 mounts a launch unit with thirty 230-millimeter diameter rocket tubes. The prominence of the launch unit is what earned it the name Buratino, a long-nosed Pinocchio-like character in a children’s story. The rockets can be fired individually or ripple-fired en masse in the space of six to twelve seconds. The vehicle also mounts a targeting computer and a laser-range finder.

Two types of rockets are equipped: ones with conventional incendiary warheads, and the fuel-air explosives discussed above. The sheer size of the rockets means that the TOS-1 requires not one but two TZM-T reloading vehicles—all-terrain trucks equipped with cranes—each carrying a full additional load of rockets.

The TOS-1 vehicle has no real counterpart in use by Western militaries. While there are all kinds of multiple-rocket launch systems in use, such as the M142 HIMARS in use by the U.S. Army to bombard ISIS in Iraq, they are all lightly armored weapons intended for long-range indirect fire.

Furthermore, such rocket artillery typically relies on cluster munitions or conventional high-explosive warheads, not incendiary ammunition. The Russian Army, however, fields long-range Multiple Launch Rocket Systems like the Smerch and Uragan, capable of using incendiary warheads. The United States uses thermobaric warheads in smaller man-portable systems as well as larger air-launched munitions.

Starting in 2001, new TOS-1A Solntsepek (Burning Sun) vehicles began entering service, with a range of six kilometers. This is sufficiently long range to allow it to fire beyond retaliatory fire from the majority of antitank weapons. The new vehicle comes with an improved ballistics computer as well. Because it fires heavier ninety-kilogram rockets, the number of launch tubes was reduced to twenty-four.

The TOS-1 and -1A are integrated into Russian Nuclear Biological Chemical (NBC) battalions. These units also field the RPO-A Shmel’ (Bumblebee) man-portable portable rocket launchers that fire smaller ninety-millimeter thermobaric charges up to a range of 1,000 meters, or 1,700 meters using the latest types. These are intended as bunker-buster weapons, as thermobaric warheads are particularly effective against structures and their occupants.

The Trail of Devastation

The first combat use of the TOS-1 Buratino is recorded between 1988 and 1989 against Afghan rebels in the rugged terrain of the Panjshir Valley. However, it was in the 1999, the same year that the TOS-1 was first revealed to the public, that the TOS-1 first made a name for itself in the siege of the Chechen capital of Grozny.

After sustaining terrible losses attempting to assault Grozny’s center during the first Chechen War, for the second war the Russian Army surrounded the city with heavy artillery and tanks. It then dispatched small infantry teams to probe the Chechen defender. Once the Chechens opened fire, the artillery surrounding the city would pulverize the city blocks from which the fire originated. TOS-1s played a major role in these bombardments, and were also appreciated for creating explosions liable to detonate mines and booby-traps left behind by the Chechen fighters.

The use of the TOS-1 to eradicate city blocks in Grozny caused a number of complaints about collateral damage. In one incident, a strike killed thirty-seven locals and wounded over two hundred. By the time the battle was over, the city had been reduced to a wasteland.

At least four TOS-1s were sold to Iraq in 2014, and they were first seen entering action against ISIS in the battle for Jurf al-Sakhar in 2014. The battle was a victory for an Iraqi Shia militia, although how much the TOS-1s contributed to that is unclear. Later video footage shows TOS-1s ripple-firing rockets on targets near Baiji, Iraq.

The TOS-1As were also given to the Syrian Arab Army, which deployed them against various Syrian rebels. Most of the footage released appears to depict bombardment of rural areas such as the mountains around Latakia, rather than inner-city locations.

However, a TOS-1 unit was recorded being used in preparation for an offensive against the city of Hama, and this June, opposition fighters posted a video apparently showing the destruction of TOS-1 near Hama by long-range antitank missiles. This highlights how the need to deploy the short-range TOS-1 closer the front line makes it vulnerable to such weapons.

A TOS-1 was also spotted by the OSCE operating in a rebel training area in Luhansk in eastern Ukraine in 2015. Ukraine does not operate any TOS-1s, so the vehicle must be of Russian origin. There is no footage of the TOS-1 actually firing rockets in Ukraine, but the Ukrainian government claims they were used in the artillery bombardment that leveled Donetsk International Airport, forcing Ukrainian forces to withdraw in January 2015. However, other powerful artillery systems, including 2S4 mortars, are known to have been used in that siege.

One of the lesser-known war zones involving the TOS-1 is the long-running conflict between Azerbaijan and Armenia over Nagorno-Karabakh. Russia has sold TOS-1As to both sides in the conflict: Azerbaijan has eighteen and Armenia was sold an unspecified number. Armenian media reported this year that an Azerbaijani TOS-1A was destroyed in fighting in April after firing rockets on the position of Karabakh separatists. Both sides claim the other initiated the skirmish.