The increasing carnage and destruction inflicted by Russian forces in eastern Ukraine — punctuated by the use of thermobaric explosives that set off huge, destructive shock waves — led to fresh accusations Friday that President Vladimir Putin was waging a genocidal campaign to wipe out a substantial part of the Ukrainian population.

A new report by international legal scholars and human rights experts said mass killings, deliberate attacks on shelters and evacuation routes, and the indiscriminate bombardment of residential areas by Russian forces had established a "genocidal pattern” against Ukrainians, in violation of the United Nations Genocide Convention.

The report, which warned that Ukrainians were at "imminent” risk of genocide, came as Russian forces captured the eastern city of Lyman after intense artillery bombardments — including from one of the most fearsome weapons in Russia’s conventional arsenal, a rocket artillery system firing thermobaric explosives. Also known as fuel-air bombs, these explosives unleash blast waves of extreme pressure and heat, raising the likelihood of civilian casualties in the surrounding area.