eastern ukraine in preparation of a large-scale assault. and what appears to be cluster munitions in a civilian area in the kharkiv region. at least four explosions seconds apart. the use against civilian targets may amount to war crimes according to the u.n. the military reports a five-hour battle overnight in the central zaporizhzhia recently. they are offering to turn over an oligarch in exchange for captured ukrainian prisoners of wars. i want to begin with the latest on the manhunt in brooklyn and new york city for whoever was responsible for opening fire on the subway behind me. jason carroll. jason, give us the latest. reporter: the bulk of the investigation is focused on