Two million people in Japan were told Saturday to seek shelter before the arrival of Typhoon Nanmadol, national broadcaster NHK said, as the weather agency issued a rare “special warning” about the powerful storm. NHK, which compiles alerts issued by local authorities, said level four evacuation instructions — the second highest — were in place for people in Kagoshima, Kumamoto and Miyazaki in the southern Kyushu region. The move came as the Japan Meteorological Agency issued its highest alert for the Kagoshima region, a warning that comes when it forecasts conditions only seen once in sever…