TUGUEGARAO, Philippines (AP) — Typhoon Mangkhut roared toward densely populated Hong Kong and southern China on Sunday after ravaging across the northern Philippines with ferocious winds and heavy rain that left at least 12 dead in landslides and collapsed houses.

The strongest storm so far this year in the world sliced across the northern tip of Luzon Island on Saturday, a breadbasket that is also a region of flood-prone rice plains and mountain provinces with a history of deadly landslides. More than 5 million people were in the path of the typhoon, equivalent to a Category 5 Atlantic hurric...