Kyiv, May 26 -- Russian strikes killed at least 12 people in Ukraine overnight, officials said Sunday, as Kyiv and Moscow traded fire even as they completed their biggest prisoner exchange since the start of the war. Ukraine's emergency services described a night of "terror" as Russia launched a second straight night of massive air strikes, including on the capital Kyiv. The attacks came even as the two countries completed their biggest prisoner swap since Moscow launched its full-scale invasion in February 2022, with 1,000 captured soldiers and civilian prisoners exchanged by each side. "Without truly strong pressure on the Russian leadership, this brutality cannot be stopped," Ukrainian President Volodymyr Zelensky said on social media. "The silence of America, the silence of others around the world only encourages Putin," he said, adding: "Sanctions will certainly help."...