Ukrainian officials on Saturday denounced a call by Russia's embassy in Britain for fighters from the Azov regiment to face a "humiliating" execution. The Russian tweet came as Moscow and Kyiv traded blame over a strike on a jail holding Ukrainian prisoners of war in Russian-controlled territory that killed around 50 people, reportedly including members of the Azov regiment. "Azov militants deserve execution, but death not by firing squad but by hanging, because they're not real soldiers. They deserve a humiliating death," Moscow's diplomatic mission wrote in an overnight Tweet. The post -- which Twitter said violated its rules on "hateful conduct" -- was accompanied by a video purportedly showing a couple in Russian-held Mariupol claiming they had been shelled by Ukrainian forces at the Azovstal metal plant during the fierce battle for the city. "Russia is a terrorist state. In the 21st century, only savages and terrorists can talk at the diplomatic level about the fact that people deserve to be executed by hanging. Russia is a state sponsor of terrorism," Andriy Yermak, head of the office of the Ukrainian presidency, wrote on Telegram. "What more evidence is...