As the conflict in Ukraine continues to rage, there are mounting fears that Russia may use – or perhaps may have already used – thermobaric weapons, also known as vacuum bombs or fuel-air explosive bombs.

Oksana Markarova, Ukraine’s ambassador to the United States, claimed that Russian forces had used a vacuum bomb against Ukrainians on Monday night, according to Reuters. Reporters from CNN also shared images of a TOS-1 or TOS-1A Multiple Rocket Launcher, capable of launching rockets with thermobaric warheads, close to the Ukrainian border just south of the Russian city of Belgorod.

For now, however, the use of thermobaric weapons in the Ukrainian conflict has not been confirmed. 

What are Vacuum Bombs?

Here’s why the possible use of vacuum bombs may be particularly worrying: it creates a powerful and indiscriminate explosion that can be notably more devastating than those made by conventional explosives, especially in urban settings near to civilians. 

Thermobaric munitions produce more heat and pressure than conventional explosives by exploding a vapor in the blast zone, as per the Journal of Military and Veterans’ Health. Thermobaric munitions work by initially dispersing an aerosol cloud into an area. This cloud flows around objects and into cracks and cavities of structures. The cloud is then ignited with a high-temperature explosion. 

What do vacuum bombs do?

Along with creating a powerful blast wave, the explosion furiously burns up all the oxygen in the blast area and the resulting vacuum "sucks up" loose objects into this void. The vacuum is said to be powerful enough to easily rupture the lungs and eardrums of anyone nearby. If close enough, the bombs can produce an array of potentially fatal injuries to the pulmonary, cardiovascular, auditory, gastrointestinal, and central nervous systems of people. 

The weapon is particularly concerning because of its indiscriminate effects when used in the vicinity of civilians. Since the aerosol cloud can penetrate into the cracks and cavities of structures, the use of vacuum bombs can be particularly devastating in urban areas, capable of turning blocks of buildings to rubble in seconds. 

Who has thermobaric weapons?

The origin of this weapon can be traced back to the German Army in World  War II fighting along Eastern Front, but the technology has since become widely developed and used in the militaries of many other countries. 

The US, for instance, has admitted to using thermobaric weapons in the mountains of eastern Afghanistan against al-Qaeda. It’s also widely believed that the UK, China, India, and — of course — Russia also have this weapon in their military arsenal. 

The use of thermobaric weapons is often criticized by non-governmental organizations, such as Amnesty International, which condemned their use by Russia in the bombing of Syria. However, they are not explicitly prohibited in warfare under international law.

All “explainer” articles are confirmed by fact checkers to be correct at time of publishing. Text, images, and links may be edited, removed, or added to at a later date to keep information current.