
What are cluster and thermobaric ‘vacuum’ weapons?

Evidence that Russia has used cluster weapons in its war in Ukraine continue to mount, with Ukrainian authorities and witnesses alleging they were used in a Russian attack on a train station in eastern Ukraine on Friday that killed at least 50 people.
Witnesses interviewed by The Post described an initial explosion at the Kramatorsk station — where hundreds of evacuees were waiting to escape a looming Russian offensive — followed by four to five blasts that they believed were “cluster bombs.”
Weapons experts who examined a photograph of a missile remnant taken by a Washington Post photographer at the scene identified it as a type of Tochka short-range ballistic missile, which can be armed with cluster warheads.
Russia denied involvement in the attack and claimed missile remnants found near the station were from weapons “used only by the Ukrainian armed forces.” But Human Rights Watch and Amnesty International have said previously that Russia has used the Tochka missile in its invasion of Ukraine.
Cluster munitions and “vacuum” weapons, another element of Russia’s arsenal that has drawn scrutiny, can put civilians at increased risk, particularly when used in urban areas.
International rights groups reported that cluster munitions apparently fired by Russia appeared to have hit a preschool in northeastern Ukraine and an area near a hospital in the Kyiv-controlled part of the eastern Donetsk region in late February, killing several civilians.
Russian forces, according to Ukraine and rights groups, also used cluster munitions in strikes on Kharkiv, the country’s second-largest city and the site of intense fighting between Ukrainian and Russian forces.
Videos shared on social media have shown Russian launchers for thermobaric weapons, often called “vacuum” weapons, rolling down Ukrainian streets. Oksana Markarova, Ukraine’s ambassador to the United States, accused Russia of using “vacuum bombs” in its invasion.
“We have seen videos of Russian forces moving exceptionally lethal weaponry into Ukraine. That includes cluster munitions and vacuum bombs — the use of which directed against civilians is banned under the Geneva Conventions,” U.S. Ambassador to the United Nations, Linda Thomas-Greenfield, said in remarks at the U.N. last month.
It remains unclear whether Russia’s use of the weapons so far would constitute war crimes, since that would depend on a legal question over the extent to which Russian forces minimized risk to civilians.
The Kremlin has denied that the Russian military used cluster or vacuum munitions during the invasion. But Britain’s defense ministry said last month that its Russian counterpart had confirmed the deployment of the TOS-1A weapon system, which uses thermobaric rockets, in Ukraine.
Here’s what to know about the weapons, their legality and the threat they pose to civilians.