Cecilia Yap: Tropical Storm Usman, which entered the Philippines on Christmas Day, has killed at least 16 people as it churned across several provinces, triggering floods and landslides and forcing thousands to flee to safer grounds.

The storm has displaced at least 17,000 people in the Bicol region in the southern part of the Philippines' main Luzon island. Three died in Albay province due to a landslide, while seven more were killed in Masbate, most of them drowning, the region's civil defense office said in a statement. Six more deaths were reported from Sorsogon and Camarines Sur provinces.

More than 6,600 people are stranded in various ports, while Cebu Air Inc. and Philippine Airlines Inc. canceled more than a dozen flights from Dec. 27 to 29.

Usman hit Philippine waters on Dec. 25 and gathered strength as it moved slowly before making landfall in the central province of Eastern Samar. While the storm has been downgraded to a low-pressure system, monsoon rain may still trigger floods and landslides, the weather bureau said. About 20 cyclones pass through disaster-prone Philippines each year.