MANILA — A tropical storm in the Philippines cut through a swath of the main southern island of Mindanao, killing at least 103 people and burying many in remote areas by landslides and mudslides just as families were preparing for Christmas, officials said Saturday.

The storm, called Tembin, slammed into the eastern portion of Mindanao late Thursday, dumping torrential rains that unleashed floods into the next day. It was expected to blow out of the country by Monday.

Heavy rains caused the banks of the Cagayan de Oro River to overflow, forcing the evacuation of nearly 20,000 people. Streets turned into virtual rivers as rescuers plucked residents from their roofs.