MANILA, Feb. 13 (Xinhua) -- A landslide caused by tropical depression Sanba killed at least four people in the southern Philippines on Tuesday, local police said.

Police said the residents were trapped inside their house in Gamuton, a village in Carrascal town in Surigao del Sur province.

Sanba made a landfall in Surigao del Sur province on Tuesday morning and it is now over the Bohol Sea after crossing the provinces of Surigao and Agusan del Norte.

State weather agency PAGASA has downgraded Sanba from a tropical storm to tropical depression, moving west northwest at 27 kilometer per hour from the previous 25 kph with maximum wind of 55 kph and gustiness of up to 80 kph.

The agency said that scattered to widespread moderate to heavy rains will prevail in the next 24 hours over Palawan and other central Philippine provinces, warning residents that the depression could bring possible flooding and landslides.

It also warned that sea travels remains risky. Thousands of sea passengers have been stranded as a result, the Philippine Coast Guard reported.