The United Kingdom has accused Russia of deploying thermobaric weapons systems in Ukraine, raising fears there could be an escalation of the damage being done as Moscow intensifies its assault on major cities a week after invading its neighbor.
"How far (Russian President Vladimir Putin) will go, what weapons he will authorize to achieve his ultimate aim, is unknown but we've seen the use of massive amounts of artillery. We've seen the deployment of thermobaric artillery weapon systems and we worry how broad those could go," British Defense Secretary Ben Wallace said on March 3 during a visit to NATO ally Estonia.
He did not elaborate.
Ukraine's government and human rights groups have already accused Russia of possibly using thermobaric weapons, while some military experts say video footage appears to show Russian military equipment capable of launching such weapons entering Ukraine during the invasion.
Russia has not commented on the issue.
Thermobaric weapons, sometimes called "vacuum bombs," basically suck in oxygen from the surrounding air to generate a higher-temperature explosion than conventional bombs.
Though not illegal, their usage is controversial because they are much more devastating than conventional explosives of similar size, and have a devastating impact on anyone caught in their blast radius.
The United States used them in Vietnam and more recently in Afghanistan to destroy mountain caves where militants were hiding.
Russia used them in its war in Chechnya in 1999 and was condemned by Human Rights Watch for doing so.
Russian-made thermobaric weapons also were reportedly used in the Syrian civil war by the regime of Bashar al-Assad.