The storm swept through several northeastern provinces in the Philippines late last week, gaining strength with sustained winds of 105 kph before moving offshore.

On Monday, government forecasters said the storm was 390km northeast off the country's coast and moving further out into the Pacific Ocean.

Landslides and flash floods are common across the Philippines from May to November during the country's monsoon season.

About 20 typhoons lash the country each year, mostly after June.

But weather officials have said changing weather patterns may have caused the unusual occurrence of the current summer storm.