The Saudi Coalition dropped a 500-pound MK-82 bomb on a Yemeni school bus, killing 54 and wounding scores of others, mostly children.

The MK-82 is an old “free fall” bomb that today is often sold with upgrade kits, making it a precision-guided munition (PGM) and thus much more accurate

If the bomb was the old-fashioned version, hitting a civilian target could be plausibly called an accident, but a guided bomb would have given the Saudis the ability to target even a moving bus. Markings recovered at the site strongly suggest that a PGM kit was part of the bomb assembly.

In 2015 Saudi Arabia ordered 20,000 PGMs from the United States, spending nearly $1.3 billion. In the 500-pound bomb category, the order included:

  • 4,020 GBU-12 Paveway II laser-guided bombs
  • 8,020 MK-82 bombs, also designated BLU-111

Paveway is a kit that attaches to conventional bombs. It consists of a seeker head, forward canards and rear tail fins, plus the electronics and pneumatic controls to move the canards and fins. Paveway-equipped munitions combine a laser seeker with an inertial navigation/Global Positioning System guidance system (INS/GPS), meaning the laser can be used for the final guidance of the bomb to the target. 

Control of a Paveway-equipped bomb is from the cockpit of the attacking aircraft, either an F-15 or F-16.

The MK-82 bomb could alternatively have the BLU-111 INS/GPS guidance kit known as the JDAM, or Joint Direct Attack Munition. The JDAM does not use laser guidance, but is still an accurate weapon which has a CEP – circular error of probability, a measure of accuracy – of approximately seven to 13 meters. When on a MK-82 500-pound bomb, the designation is GBU-38/B – Guided Bomb Unit 38/B.

The MK-82 with a guidance kit can be quite accurate. In Operation Desert Storm in 1991, it is reported that bombs equipped with GBU-12 laser bomb kits hit their targets 88% of the time and most of the targets struck were vehicles.

A look at the burned out school bus suggests that the bus was blown up either in a direct hit or very nearly a direct hit. Immediately around the blasted bus were some small shops, nothing military. Only the shell of the bus, twisted but recognizable, survived the blast.

Was the Yemeni school bus “collateral” damage, a mistake or a deliberately chosen target? We don’t know, but the Saudi comments suggest the school bus was targeted.

The use of modern weapons against civilian targets is a very complicated issue. In asymmetric warfare it is even tougher because terrorists often operate from inside schools, hospitals, apartment blocks and mosques. Occasionally, terrorists put civilians on the rooftops of buildings which they use for headquarters or for hiding missiles, as was done by Hamas in Gaza.

The difficulty of targeting the enemy while avoiding civilian casualties has led the United States to work on weapons of higher accuracy with lower chances of collateral damage. One result is the small-diameter bomb, a 250-pound bomb that has combined radar, infrared and laser target designator and INS/GPS guidance.

Some countries, notably Israel, not only practice precision targeting, but also warn civilians who may be co-located with terrorists to vacate a building or facility before it is attacked. In one incident reported in 2014, A Palestinian woman received a cell phone call from someone who knew her name and told her she and her family had five minutes to get out of the building they were in. 

This tactic, called “roof knocking,” combines phone calls and sometimes small rockets or flares to encourage people to get out of harm’s way.

Despite such efforts by the US, Israel and other US coalition air forces, there have been many civilians killed by aerial bombardment. The Syrian Air Force, for example, makes no excuses for targeting apartment blocks, hospitals and schools. They use barrel bombs, sometimes stuffed with nails and high explosives, other times filled with chlorine gas – weapons that routinely kill civilians trapped in areas held by rebels. In many cases the victims are women, children and the elderly.

The Russians operating in Syria are not much better, even though the Russians have precision guided munitions.

In the case of the Yemeni school bus, the Saudis may have believed the passengers were Houthi troops. Coalition spokesman Colonel Turki al-Malki told CNN that the airstrike was aimed at a “legitimate target” implying, if not saying, that the school bus was not filled with kids but with combatants.

“No, this is not children in the bus,” he said. “We do have high standard measures for targeting.” 

The use of civilian vehicles by terrorists and revolutionaries is not at all uncommon. For example, the Taliban used an ambulance stuffed with explosives to kill 95 civilians in Kabul. In Israel, Hamas terrorists filled ambulances full of children and used them in front of command centers as human shields.  

Civilian school buses have been targeted by terrorists. In 2011 in Shaar HaNegev, an Israeli school bus was attacked by Hamas terrorists using a Russian-made Kornet antitank missile. One student died.

In 2017 in lower Manhattan, a school bus was rammed by a rented truck in a terror attack.

The latest incident in Yemen is not the first time the Saudi coalition has hit a civilian target. In one of the worst instances, Saudi coalition aircraft attacked a funeral in Sana’a, killing 155 people and wounding more than 525. 

This, the UN said, was a “double tap” attack because a second attack came some five minutes after the first – hitting those who came to rescue the first set of victims. The Saudis said the target information had been given to them by the Yemen government and turned out to be wrong, but one wonders what the pilots were looking at or why there was a second strike aimed at first responders? 

The funeral  attack also featured MK-82 bombs with laser guided bomb kits.

The Saudi government announced it will investigate the school bus attack, but has not invited any independent third party to participate in the investigation, so its impartiality is in doubt.

Saudi Arabia and its partners need to put in place clear policies aimed at minimizing civilian casualties, and the US as the weapons supplier needs to push Saudi Arabia to get serious about how it uses American-supplied weapons.