Russia and Ukraine exchanged strikes overnight and Sunday, killing at least eight people in Ukraine and one in Russia, officials said, hours after Moscow rejected German calls to ease off its escalation toward NATO.

By Kyu-seok Shim and Rishabh Jaiswal Sept 27 (Reuters) - South Korea's presidential office demanded an official explanation and apology from Ukraine, accusing Kyiv of disclosing the transfer of two North Korean prisoners of war to South Korea and then falsely denying that the two sides had agreed to keep the move confidential.