Russian attacks on Ukraine have killed at least 22 people, including 12 in one of the worst strikes so far this year, as the deadline approached for a Ukrainian proposal for an open-ended ceasefire to begin at midnight.Russia announced a ceasefire for May 8-9, dates when it commemorates the Soviet Union victory over Nazi Germany in World War II and holds a military parade.Ukraine, in response, announced a proposal for an open-ended ceasefire starting at midnight on Wednesday, urging Russia to reciprocate.President Volodymyr Zelenskiy said it was not an option for Russia to halt strikes for one day for its...