Human rights groups say Russia has used thermobaric weapons in its assault. These so-called vacuum bombs are the most powerful non-nuclear explosives used in warfare. Meanwhile, Human Rights Watch documented a Russian cluster bomb attack on a hospital in eastern Ukraine that killed four civilians and injured another 10 people. A United Nations treaty banning the use of cluster munitions has been signed by over 100 nations — although Russia, Ukraine and the United States have refused to sign on to the prohibition.

On Monday, Ukrainian President Volodymyr Zelensky accused Russia of war crimes for deliberately targeting civilians. He spoke after Russian and Ukrainian officials met on the Belarusian border to discuss a possible ceasefire. Those talks failed.

President Volodymyr Zelensky: “These talks took place while our territory, our cities were being bombed and shelled. We could see the synchronization of the shelling with the negotiation process. I believe that in this unsophisticated way Russia is trying to apply pressure. Don’t waste our time. We do not accept such tactics.”

Earlier today, President Zelensky addressed the European Parliament by video link. On Monday, he called on the European Union to grant Ukraine immediate membership to the 27-nation bloc.