By Simon Lewis KREMENCHUK, Ukraine (Reuters) -A Russian missile strike killed at least three people in a residential building in southern Ukraine on Wednesday, authorities said, as the search continued for dozens still missing from an attack on a shopping mall two days ago. Eight missiles struck the southern city of Mykolaiv including an apartment building, Mayor Oleksandr Senkevych said, just days after Ukraine said Russian missiles killed at least 18 people at a mall in the central town of Kremenchuk. Photographs from Mykolaiv showed smoke billowing from a four-storey building with its upper…